Answer:
Magnifying glass or a special device that resembles a handheld microscope, used to observe ink placement of printers
Explanation:
A sample of gallium exists as two isotopes, 69 Ga, relative abundance of 61.2%, and 71 Ga, relative abundance of 38.8%. Calculate the relative atomic mass of gallium. Pls, help me!!!
The relative atomic mass of gallium, given that it exists as two isotopes is 69.776 amu
From the question given above, the following data were obtained:
Mass of isotope A = 69Abundance of A (A%) = 61.2%Mass of isotope B = 71 Abundance of B (B%) = 38.8%Relative atomic mass =?How to determine the relative atomic massThe relative atomic mass of the isotope can be obtained as illustrated below:
Relative atomic mass = [(Mass of A × A%) / 100] + [(Mass of B × B%) / 100]
Relative atomic mass = [(69 × 61.2) / 100] + [(71 × 38.8) / 100]
Relative atomic mass = 42.228 + 27.548
Relative atomic mass = 69.776 amu
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Which of the following has the largest second ionization energy and WHY?
A) Ca
B) Ga
C) Ge
D) K
E) Se
Ca has the largest second ionization energy of 589.8 kJ/mol .
The second ionization energy of an element is usually greater than the first because positive charge more strongly attracts electrons than negative charge.
What is ionization energy?Ionization energy, also known as ionization energy, is the minimal amount of energy needed to liberate the most loosely bound electron from an isolated gaseous atom, positive ion, or molecule in physics and chemistry.
Ionization energy, also known as ionization potential, is the quantity of energy needed to remove an electron from an isolated atom or molecule in physics and chemistry.
Ionization energy can be defined simply as a measurement of how difficult it is to remove an electron from an atom or ion or of an atom's or ion's propensity to give up an electron.
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The four essential elements for life are _______. a. carbon, hydrogen, oxygen and nitrogen b. carbon, hydrogen, oxygen and iron c. carbon, nitrogen, oxygen and magnesium d. iron, nitrogen, oxygen and magnesium please select the best answer from the choices provided a b c d
Explanation:
it suppose to be oxygen hydrogen nitrogen and phosphorus
its A fr fr ong like this is fax
consider the following questions about polyprotic acids and determine if each statement is true or false. for polyprotic acids ka1 is typically much smaller than ka2 for most polyprotic acids, each proton dissociation can be looked at separately for most polyprotic acids all ka values must be considered to determine the ph of the solution
For polyprotic acid ka1 is greater than ka2 , each proton dissociation can be looked at sepatertely and all the ka values must be not considered to determine the PH.
Polyprotic acids is a substance capable of donating more than one proton. Di protic and tri protic are the one capable of donating two o three proton,respectively.
For polyprotic acid ka1 is smaller than ka2 is not correct. for polyprotic acid ka1 is greater than ka2 as they have tendency to give off more than one H+ ion.
The proton dissociation can be looked at separately for most polyprotic acid is correct . each proton dissociation can be look at separately.
All ka values must be consider to determine the PH of solution is not correct.we can use ka1 as an approx because ka2 is considerably smaller no.
Thus, for polyprotic acid ka1 is greater than ka2, each proton dissociation can be looked at separately and all the [tex]K{a}[/tex] values must not be considered to determine the PH.
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What is true about these two pictures? PLS HELP ME
Both A and B are molecules.
Both A and B are elements.
A is a compound, but B is an element.
A is an element, but B is a compound.
Answer:
Both A and B are molecules.
The answer is: To think of different kinds of materials to use
Glass, Metal, Wood, Ceramic, Plastic are different kind of materials to be used.
Glass is versatile material, which is made up of sand and silicon dioxide. Most familiar glass today is soda-lime silica glass. they have properties like hardness, transparency and heat resistance.
Metals are the important materials found in earth and they are used in a vide variety of applications. Aluminium, iron and copper are some of the examples of metals. they can combined together to makes alloys. they have properties like conductivity, lustre and malleability.
Wood is the most common and easily available material. two kinds of wood are there hardwood and softwood. they are used in construction and as fuel for burning.
Ceramic are substances which are inorganic and non-metallic in nature. they are used to make pots, vessels etc. they are hard, heat resistant, and resistant to corrosion
Plastic are up of long chain of molecules. they are used in the production of variety of substances.. there are different types of plastics. they are cost friendly, strong and durable, resistant to water and electricity.
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What is the mass of an object when the triple beam balance reads 100.00 g, 20.00 g, 0.20 g, and 0.05 g?
How many moles of atoms are in 50 atoms Ba
moles of atoms in 50 atoms of barium are 301.15 × 10^23
We may determine how many chemicals or particles are included in one mole using Avogadro's number.Chemistry's fundamental building block is an atom. It is the smallest fraction of matter into which electrically charged particles cannot be released. It is also the smallest piece of substance with chemical element-like characteristics.A mole of any substance is equal to 6.023 x 10^23, or Avogadro's number. Additionally, it is employed to express concentrations in terms of moles per litre or molecular weight.The number of atoms in exactly 12 grammes of pure carbon-12 is the value of a mole.Chemical element barium has the chemical symbol Ba and atomic number 56. In group 2, it is the fifth element.1 mole of substance = 6.023 x 10^23
so in 50 atoms of Ba = 50 × 6.023 × 10^23
= 301.15 × 10^23
Therefore, moles in 50 atoms of Ba is 301.15 × 10^23.
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22. A
is a way of organizing data that is used to show
changes that occur in related variables.
Obar graph
O circle graph
Oline graph
O table
Answer:
line graphs
hope this helps :)
The density of enthanol is 0.789 g/ml at 20 c what is the mass of a sample of ethanol at this temperature that has a volume of 175.0 ml?
The mass of a sample of ethanol at 20°C is with volume 175.0 mL and density 0.789 g/mL is 138.075 g.
Density is defined as the mass of a substance per unit volume. It is denoted by ρ.
The mass of a substance when the density and volume is given can be found by using the formula -
Density = mass
volume
ρ = m
v
Given data -
volume of ethanol = 175.0 mL
density = 0.789 g/mL
So, the mass is -
Mass = density x volume
mass = 0.789 g/mL x 175.0 mL
mass = 138.075 g
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Which of the following does not describe a physical property of iron?
A
B
C
D
Iron is silvery-white or gray in color.
Iron has a boiling point of about 3,000°C.
Iron is a magnetic element.
Iron and sulfur react to form iron sulfide.
BACK
Answer:
D: Iron and sulfur react to form iron sulfide.
Explanation:
To make iron sulfide you need to combined Iron and Sulfur atoms, producing a chemical reaction.
An object has a mass of 12.5 grams and a volume of 2.7 mL
what is the object's density?
Answer:
[tex]4.6\frac{g}{mL}[/tex]
Explanation:
The formula for finding a object's density is:
D = M/V, which means Density equals Mass divided by Volume.
In this case, our mass is 12.5 grams, our volume is 2.7mL, and our density is the unknown we are solving for.
One important thing to keep in mind when finding density is the type of measurements used. Fortunately in this case, we are dividing grams by ml, which have a 1:1 conversion rate.
To find our answer, we just divide 12.5 by 2.7 to get:
[tex]\frac{12.5g}{2.7mL} = 4.6\frac{g}{mL}[/tex]
The true answer is 4.629, where 629 is repeating. However when we apply significant figures, we see our lowest amount of sig fig is 2 digits(in 2.7), so we round to 2 digits in our answer.
Hope this helps!
Inside Earth, it is very hot and this source of heat called
Answer:
Geothermal energy
Explanation:
Hope that helps !!!
Marco put a pot of water on to boil eggs. after a few minutes all the water was This is an example of _____.
Multiple choice question.
A)
condensation
B)
deposition
C)
sublimation
D)
vaporization
Answer:
D) vaporizationExplanation:
Marco put a pot of water on to boil eggs. after a few minutes all the water was dry
This is an example of vaporization.hopefully this helps you!
Is the anser A b c or d
An object can accelerate only when there is a net force being applied.
As we can see in the image given in question that object 1 has forces with identical magnitude of forces being applied to opposite sides. The two opposite forces with identical magnitude will cancel the effect of each other on the object 1 and the net force on object 1 will be zero. And for this reason object 1 remains stationary.
In another case object 2 has forces with different magnitudes being applied to opposite sides. As the magnitude of forces applied on object 2 are different, these opposite forces after cancelation will have some net force acting on object 2. For this reason object 2 is accelerating. So, option a is correct i.e., An object can accelerate only when their is net force being applied.
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3. Give 2 examples of intensive properties
Answer:
examples of intensive properties are colours and density
A 2.00g sample of C2H5OH undergoes condensation. The molar enthalpy of vaporization, ΔHvap, of C2H5OH is +38.6kJ/mol. Which of the following best identifies the change in enthalpy in the phase transition?
A) +19.3 kJ
B) +77.2 kJ
C) -19.3 kJ
D) -77.2 kJ
The change in enthalpy in the phase transition is -1.6598 KJ/mol.
As the enthalpy of vaporization and enthalpy of condensation are just the same with only difference being in their signs.The enthalpy of condensation of ethanol is -38.6 KJ/mol .For 2 g sample the enthalpy is calculated as,
number of moles of ethanol=2/46=0.043 moles
38.6 KJ of heat is absorbed for condensation of one mole of ethanol.
Therefore,heat absorbed for condensation of 0.043 moles of ethanol is,
-38.6×0.043=-1.6598 KJ
What is enthalpy of condensation?The enthalpy of condensation is defined as amount of heat which is released when a substance undergoes transformation from gas to liquid phase.Less energy is required to change from solid to liquid than from a liquid to gas.It has units of KJ/mol.
Condensation is an exothermic process as heat is absorbed and is given off from the system into the surroundings. It possesses values which are always negative.
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Your question is incomplete, but most probably the options were:
A)+19.3 KJ
B)+77.2 KJ
C) -19.3 KJ
D)-77.2 KJ
E)-1.6598 KJ
What is the purpose of photoreceptors?
a. They focus the light coming into the eye.
b. They contract and relax to control the pupil.
c. They change light to electrical signals.
d. They receive light and turn it into an image.
The purpose of photoreceptors are they 'convert light to electrical signals'
Photoreceptors are the cells in the retina that respond to light and in that special cells in the eye's retina that are responsible for converting light into signals that are sent to the brain and photoreceptors give us our color vision and night vision and there are two types of photoreceptor cells rods and cones. when light hits the retina special cells called photoreceptors turn the light into electrical signals. these electrical signals travel from the retina through the optic nerve to the brain and then the brain turns the signals into the images called photoreceptors and the best example is human eye retina is a good example of photoreceptor protein
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Which blood vessels serve the body cells?
Veins
Arteries
Capillaries
Plasma
Answer: The blood vessels that serve the body cells is Capillaries.
Explanation: The tiniest blood vessels in the body, capillaries link the tiniest arteries to the tiniest veins. Because they provide oxygen and nourishment to every cell in the body and remove carbon dioxide so that it may be expelled, these capillaries are frequently referred to as the "microcirculation."
How to convert a velocity of 2.03x10 to the -9 cm/min. to m/s.
The velocity in m/s will be 0.03 x 10^-11 m/s
2.03x10^-9 cm/min x 1 m/100 cm x 1 min/60 sec =
0.03 x 10^-11 m/s
What is Velocity ?As a vector measurement of the rate and direction of motion, velocity is defined. Velocity can be defined as the rate of movement in one direction. Velocity may be used to calculate the speed of a car moving north on a major motorway and the speed of a rocket launching into space.
There are several various forms of velocity, including uniform, variable, average, and instantaneous.According to the equation v = s/t, velocity (v) is a vector quantity that quantifies displacement (or change in position, s), over change in time (t).Learn more about Velocity here:
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Which sentence from the article BEST supports the idea that not all liquids evaporate at the same temperature?
A
The temperature at which a liquid turns into a gas is called its boiling point.
B
That same temperature can be considered the melting point if the temperature is increasing and causes a solid to become a liquid.
C
For example, liquid water turns to a solid form — ice — when it is cooled to 32 degrees Fahrenheit (0 degrees Celsius).
D
Different types of matter have different boiling, melting and freezing points.
The sentence which BEST supports the idea that not all liquids evaporate at the same temperature is: Different types of matter have different boiling, melting and freezing points; option D
What is evaporation?Evaporation is the process by which a liquid substance spontaneously changes to liquid.
Evaporation of a liquid is affected by the following factors:
the nature of the liquidthe boiling point of the liquidthe presence of windrelative humiditySubstances with low boiling point usually evaporate at a faster rate tan substances with higher boiling points.
However, due to the nature of various substances, different types of matter have different boiling, melting and freezing points. Thus, not all liquids evaporate at the same temperature.
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Can someone help me finish this? (images attached)
Answer: Number 7 is molecules, Number 3 is the nuclear force, Number 8 is chemical
Explanation: For number 3 I don't know what other name is their for the nuclear force.
I hope this helped!
How many molecules of water are required for the hydrolyzation of a polymer that is 22 monomer-long cellulose molecule?.
21 molecules of water are required for the hydrolyzation of a polymer that is 22 monomer-long cellulose molecule.
For hydrolyzation of 22 monomer-long cellulose molecule, 21 molecules of water are required. As for three monomer polymer there are 2 bonds so we require two water molecules.
The process of hydrolyzation is a step-by-step reaction in which-
The first step is the condensation of one glucose molecule to produce a 2 monomer-long chain, which releases one molecule of water.
The second step is reaction between the 2 monomer-long chain with other glucose molecule, which release an extra molecule of water.
These steps are repeated until 21 condensation reactions occurs, to give 22 monomer-long cellulose molecule.
The OH group from first monomer of the glucose unit and H group from second monomer is removed in the form of water molecules, when polymer bond is formed.
The reaction is known as the condensation reaction. It is referred to as the loss of water in a chemical reaction.
Therefore, 22 monomer long cellulose molecule indicates 21 reactions of condensation with release of 21 molecules of water.
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The km of an enzyme is 5. 0 mm. Calculate the substrate concentration when this enzyme operates at one‑quarter of its maximum rate.
The substrate concentration of this enzyme operates at one‑quarter of its maximum rate is = 0.333.
What is the relationship between Km and substrate concentration?In practice, Km is the concentration of substrate that allows the enzyme to achieve half Vmax. An enzyme with a high Km has a low affinity for its substrate and requires a higher concentration of substrate to achieve Vmax." Because Km is a constant, increasing the substrate concentration has no effect on it. The substrate concentration Km corresponds to the substrate concentration at which the reaction rate of the enzyme-catalyzed reaction is half of the maximum reaction rate Vmax.Steps of the equation :
[tex]V_{0} = \frac{V_{max}[5] }{[5]+Km}[/tex]
Fraction of [tex]V_{max}[/tex] :
[tex]\frac{V_{0} }{V_{max}} = \frac{[5]}{[5] + Km} = \frac{0.5 Km}{1.50 + Km} = 0.333[/tex]
The substrate concentration of this enzyme operates at one‑quarter of its maximum rate is = 0.333.
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check my answers! please hurry ive been working on this test for over 2 hrs lol
Question 1: The periodic table is arranged by various patterns. Is there a pattern with regard to ionic charge? In three to five sentences, explain your reasoning and provide specific examples.
Question 1 Answer: Negative ions increase in magnitude from right to left, whereas positive ions increase in magnitude from left to right. This is due to the fact that the left side of the periodic tale contains metals whereas the right side does not. As negative-charged electrons are always produced by metals, the element will become more positive when they are lost.
Question 2: Moving from the element with atomic number 10 to atomic number 11 on the periodic table, there is a change in reactivity. In three to five sentences, identify the direction of the change, and give two reasons for the change.
Question 2 Answer: The atomic number of sodium is 11, while neon is 10. Since neon has an outer shell made entirely of electrons, it doesn't interact with the other elements. The extra electron in sodium is located in the outer shell and there is one extra proton as well. By either losing one electron or gaining seven more, it might fill that shell. Since it will start losing that electron, sodium is a much more reactive element then neon.
Positive ions grow in magnitude from left to right, while negative ions grow in magnitude from right to left.
What are ions?Any atom or collection of atoms with one or more positive or negative electrical charges is known as an ion.
The periodic table shows that there are more valence electrons on the right than the left. The maximum amount of ionic charge that an element can hold fluctuates as the number of valence electrons rises.
Second, metals on the periodic table's left side primarily produce positively charged ions. These ions get stronger over time, increasing in size.
The negative charges on the ions that non metals on the right side of the periodic table produce have a diminishing magnitude over time.
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When incorporated into a polypeptide chain not at the n or c terminus, _______ would make the charge of the polypeptide more positive.
When incorporated into a polypeptide chain not at the n or c terminus, Arginine would make the charge of the polypeptide more positive.
Do humans require arginine?Because arginine is an essential amino acid for young organisms' optimal growth and development, it must be provided in the diet. Arginine is a conditionally essential amino acid for adults, particularly in conditions such as trauma, burn injury, small-bowel resection, and renal failure.L-arginine is an amino acid that aids in protein synthesis in the body. It also causes nitric oxide to be released into the bloodstream. According to a 2016 review, nitric oxide acts to widen blood vessels in the bloodstream, which may help with certain circulatory conditions. The substance also stimulates insulin release in the body.Because L-arginine relaxes blood vessels, it may benefit men suffering from erectile dysfunction (ED) caused by poor blood flow. It may improve the efficacy of medications such as sildenafil (Viagra). Taking L-arginine with ED medication may cause blood pressure to drop too low.To learn more about Arginine refer to
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When a student is recording descriptions such as the color and shape of a rock specimen, the student is making a(n) __________.
A)
hypothesis
B)
inference
C)
theory
D)
qualitative observation
E)
quantitative observation
When a student is recording descriptions such as the color and shape of a rock specimen, the student is making a qualitative observation.
To geologists, rocks are natural substances made up of solid crystals of various minerals fused together into a solid mass. Minerals may or may not be formed at the same time. The point is that a natural process tied them all together. Weathering is a major deformation of rocks.
Heat and pressure form common rocks, but dramatic changes in their shape correspond to weathering because weathering breaks rocks from large structures into small mineral particles. These white bands or streaks, often called veins, are quartz or calcite. Quartz-filled crevices and fissures in the rock. Calcite was formed by the precipitation of calcium carbonate from water flowing over rocks.
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Answer:
Qualitative observation
Explanation:
There is a common difference between qualitative and quantitative observation
Quantity related observation such as mass of rock comes under quantitative observationBut here the color and shape is observed so it's qualitative observation
option D
The usual soda pop can contains 360 mL. How many such cans could be filled from one 2.0 L bottle?
If there is a usual soda pop that contains 360 mL then the number of cans that can be filled from 2.0 L bottle are 5.5 pop cans.
Amount present in one soda can = 360 mL
Total amount present = 2.0 L
Convert 2.0 L into mL
1 L = 1000 mL
2.0 L = 2.0 x 1000 mL
= 2000 mL
So, the total amount = 2000 mL
Number of can using 360 mL = 1
The number of soda pop cans that can be filled using 2000 mL
= 2000 x (1/360)
= 2000/360 = 5.5 pop cans
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An object is traveling at a speed of 500.0 m/sec. How fast is that in km/hr?
Answer:
0.5km/hr
Explanation:
[tex]500.0 \div 1000[/tex]
this is because to get from n to KM you have to divide by 1000
A graduated cylinder has a mass of 80.0 g when empty. When 20.0 mL of water is added, the
graduated cylinder has a mass of 100.0 g. If a stone is added to the graduated cylinder, the water level rises to 45.0 mL and the total mass is now 156.0 g. What is the density of the stone?
Answer:
2.24g/
Explanation:
mass of water is found by getting 5he extra mass the cylinder gained after adding
100g-80g=20g - mass of water
Density of water: 1g/cm³ that means that 20g water has a volume of 20cm³
1cm³=1ml; 20cm³=20ml
volume of stone is the extra height the water gained: 45ml-20ml =
25ml
mass of stone is the extra mass now earned:
156g-100g=56g
Density of stone=mass of stone÷divide by volume of stone
56g÷25ml=
2.24g/ml