Using Avogrado's constant (6.022e23):
4(6.022e23) = 2.41e24
Please help
15 points
Given
Atomic symbol
RequiredAtomic composition
Solution
Atomic number = number of protons = number of electrons
Mass Number (A) is the sum of protons and neutrons
Number of protons and Number of Neutrons in nucleus
Number of electrons in the shell
From the picture:
protons = 3
neutrons = 4
electrons = 3
atomic number = protons = electrons = 3
mass number = protons + neutrons = 3+4 = 7
How many molecules are in 97.21 grams of Sodium Chloride (NaCl)?
The acid digestion test left 2.595 g of fiber from a composite specimen weighing 3.697 g. The composite specimen weighs 1.636 g in water. If the specific gravity of the fiber and matrix is 2.5 and 1.2, respectively, find the 1. Theoretical volume fraction of fiber and matrix 2. Theoretical density of composite
Answer:
0.4323 ; 1.5394
Explanation:
Given that :
Specific gravity of Fibre (Sf) = 2.5
Specific gravity of Matrix (Sm) = 1.2
Mass of Fibre, Mf = 2.595g
Weight of composite specimen in water , Wc = 1.636g
Composite weight, Ww = 3.697 g
Weight of Fibre and matrix
Volume fraction of Fibre and matrix :
[(Mf/Sf) ÷ (Mf/Sf + Wc/Sm)] * 100
[(2.595/2.5) ÷ (2.595/2.5 + 1.636/1.2)]
(1.038 ÷ 2.4013333)
= 0.43225986
= 0.4323
2.)
Theoretical density of composite :
Weight of composite / (Mf/Sf + Wc/Sm)
3.697 / (2.595/2.5 + 1.636/1.2)
3.697 / 2.4013333
= 1.5395613
= 1.5394
WORTH 35 POINTS! MY LIFE DEPENDS ON IT HELP!
When naming ionic compounds, always
1. use prefixes
2. write the metal first
3. write the nonmetal first
4. capitalize the metal and nonmetal
Answer
2.Write the metal first ( if I am right) as it is ionised
which type of electromagnetic radiation is used in security baggage scanners
X-rays, because
I did it and got it right
Answer:
XX-rayX-ray
Explanation:
A given compound has the following solubility properties. At room temperature, it is soluble in diethyl ether but insoluble in both ethanol and water. At higher temperatures, it is soluble in both diethyl ether and ethanol, but insoluble in water. Propose a procedure for purifying this compound by recrystallization.
Answer:
See explanation
Explanation:
If we desire to recrystallize the given compound then we must do the following;
1) Add the compound to ethanol and heat the system
2) As the solute dissolves, the solution is allowed to cool
3) The solution may be seeded or the vessel scratched to aid crystallization.
4) The pure crystals are now filtered out, washed and dried.
Remember that recrystallization has to do with dissolving a solute in a solvent in which it is only soluble at high temperature but insoluble at low temperature.
The solvent dissolves the impure solute while pure crystals emerges as the temperature decreases.
Which refers to any disturbance that carries energy from one place to another?
Answer:
A wave
Explanation:
A wave is a disturbance that carries energy from one place to another. Matter is not carried with the wave but instead a wave can move through matter.
Answer:
A Wave
Explanation:
Which color of light does a green object absorb?
Answer:
Magenta.
Explanation:
Color absorption is a process that occurs when a light wave strikes an object. When a light wave strikes an object it either absorbs color or transmits the color, or reflects the color. When a light wave strikes a green object, it absorbs a magenta color.
Magenta is a combination of red and blue light, therefore, the colors that the green object will absorb is red. blue, or magenta light.
How do atoms of copper differ from atoms of aluminum? *
They are not pure substances.
They have different chemical properties.
They can be formed by physical changes.
They are made up of more than one type of particle.
Answer:
The copper atoms are smaller than the aluminum atoms so more copper atoms fit in the same volume. ... Copper is more dense than aluminum. The copper must be more dense because when you compare equal volumes of the two substances, the copper has greater mass
Which of the following materials will conduct electricity well?
Cotton
Metal
Rubber
Wood
Answer:
Metal
Explanation:
Rubber and Wood are insulators. and Cotton is neither a insulator nor a conductor. But Metals are conductors
Question asked: Which of the following materials will conduct electricity well?
Answer: Metal
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I hope this helps!
1. Which list of nuclear emissions is arranged in order from the least penetrating power to
the greatest penetrating power?
A) alpha particle, beta particle, gamma ray
B) alpha particle, gamma ray, beta particle
C) gamma ray, beta particle, alpha particle
D) beta particle, alpha particle, gamma ray
Answer:
A) alpha particle, beta particle, gamma ray
Explanation:
Alpha beta and gamma radiations are the examples of ionizing radiations. When an atom is an excited state and having high energy, the atom is in unstable state. The excess of energy is released by the atom to get the stability. The released energy is in the form of radiations which may include alpha, beta, gamma, X-ray etc.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Beta radiations:
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminum is used to block the beta radiation
⁴₆C → ¹⁴₇N + ⁰₋₁e
The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.
Gamma radiations:
Gamma radiations are high energy radiations having no mass.
These radiations are travel at the speed of light.
Gamma radiations can penetrate into the many materials.
These radiations are also used to treat the cancer.
Lead is used for the protection against gamma radiations because of its high molecular density.
The lead apron are used by the person when treated with gamma radiations.
Lead shields are also used in the wall, windows and doors of the room where gamma radiations are treated, in-order to protect the surroundings.
Breathing equipment used by rescue workers needs to capture the CO2 the humans breath out and produce O2 for them to breath in, like a plant during photosynthesis. One compound capable of doing this is potassium superoxide (KO2), which produces the salt by-product potassium carbonate. What is the balanced chemical equation for this reaction? Don't include states of matter.
Answer: [tex]4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:
[tex]4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2[/tex]
A magnetic field protects Earth from the Sun's high-energy particles. What two processes are involved in the formation
of Earth's magnetic field?
the movement of materials in Earth's mantle and Earth's rotation
the movement of metals in Earth's core and Earth's rotation
the movement of solar wind toward Earth and Earth's revolution
the movement of eruptions from the Sun's surface and Earth's revolution
Answer:
B
Explanation:
Answer:
definetly b
Explanation:
Ok so I don't understand how to do this-
Can someone explain how?
Shanghai, China (31° N, 121° E)
1. 24-hr Average Yearly Temperature in ºC
2. Total Yearly Precipitation in mm
Answer:
Oh, you are supposed to look up the yearly temp, and yearly rain for a certain area. I did this before!
Convert 76.78 g of CO2 to a volume.
________ gas is evolved in cathode during the electrolysis of water. 20 points answer fast
Answer:
hydrogen
Explanation:
In electrolysis of water, gas evolved at cathode is hydrogen
What is a personal factor of resilience?
A. Feeling of belonging
B. Family and friends
C. Genetics
D. Coping Mechanisms
Answer:
B
Explanation:
B is a personal factor of resilience
explain the difference between aldehyde and ketones
Answer:
You will remember that the difference between an aldehyde and a ketone is the presence of a hydrogen atom attached to the carbon-oxygen double bond in the aldehyde. Ketones don't have that hydrogen. ... Aldehydes are easily oxidized by all sorts of different oxidizing agents: ketones are not.
A student wants to know if the weight of a cart affects its speed at the bottom of a ramp. He can change the weight of the cart by adding different numbers of balls, and he can change the height of the ramp by using different numbers of blocks. Which set of tests should he compare? MARKING BRAINLIEST
Answer:d
Explanation:
Part A Indicate whether each statement is true or false. Sort these statements into the proper categories. ResetHelp NaClNaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.NaClNaCl dissolves in water but not in hexane because the enthalpy of mixing NaClNaCl with water is more negative than that of mixing NaClNaCl with hexane.NaClNaCl dissolves in water but not in benzene (C6H6)(C6H6) because there are no hydrogen bonds in benzene. True False
Answer:
Explanation:
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
This statement is true . NaCl is ionic compound . I water is ionises strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane.
This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene.
This statement is wrong . NaCl does not make hydrogen bond with water molecule .
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.This statement is true .
What is an ion ?The term ion is defined as an ion is an atom or molecule with a net electrical charge. There are two types of ions that are cation and anion.
This statement is true . NaCl is an ionic compound . The water is ionizes strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane. This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene. This statement is wrong . Because NaCl does not make hydrogen bond with water molecule .
Thus, NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
To learn more about an ion, follow the link;
https://brainly.com/question/14982375
#SPJ2
cellular respiration uses glucose and oxygen to make
Answer:
The answer is: ATP
(Im pretty sure)
What element has 12 protons, 12 neutrons and 12 electrons?
Answer:
magnesium atom
The most common and stable type of magnesium atom found in nature has 12 protons, 12 neutrons, and 12 electrons
With respect to conductivity, select the statement that is true.
NEED ASAP PLZ
Select one:
a. Acids are good electrical conductors, but not bases or neutral substances like water.
b. Water is a good electrical conductor, but not acids or bases.
c. Acids and bases are good electrical conductors, but not neutral substances like water.
d. Acids, bases, and water (neutral) are all good electrical conductors.
A chemist carefully measures the amount of heat needed to raise the temperature of a 894.0g sample of a pure substance from to −5.8°C to 17.5°C. The experiment shows that 4.90kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance?
Answer:
C = 0.2349 J/ (g °C)
Explanation:
Mass, m = 894.0g
Initial Temperature = −5.8°C
Final Temperature = 17.5°C
Temperature change = 17.5°C - (−5.8°C) = 23.3
Heat, H = 4.90kJ = 4900 J
Specific heat capacit, C = ?
The relationship between these quantities is given by the equation;
H = mCΔT
C = H / mΔT
C = 4900 / (894)(23.3)
C = 0.2349 J/ (g °C)
Pls answer this two ASAP PLSSSSSSSS
Answer:
1. aa
2. They have similar DNA
Explanation:
1. According to the question 1, wrinkled seeds (A) are dominant over round seeds (a) in pea plants. This means that, based on the law of dominance proposed by Mendel, wrinkled seeds will be expressed over round seeds in a heterozygous state (Aa).
However, since the round seed phenotype is a recessive trait, it will only be expressed when the alleles for round seeds (a) are the same in the gene i.e. aa genotype.
2. Based on the information in question 2, Ricky, who is working on a family tree for his school project, realizes that his close relatives all look similar in the pictures he collected. This is possible because of the SIMILARITY OF THEIR DNA (genetic material). Note that, relatives are connected by the genes that are inherited from one another, hence, they possess a similar DNA, which is the most valid reason for the resemblance.
There is a third bromobutene structure that could have been formed in the addition of HBr to butadiene: cis-1-bromor-2-butene (the cis isomer of structure 2). Draw this structure. Would you predict (no calculation) its heat of formation to be more or less negative that the trans isomer? Explain.
Answer:
its less negative hope I helped buster
Because trans isomers are more stable than cis isomers, the cis isomer will have a less negative heat of formation than the trans isomer.
What are cis- and trans- isomers?Cis- and trans isomers are compounds that have different configurations in space because of the presence of a rigid structure or functional groups in their molecule.
Cis atoms have functional groups on the same side.
Trans isomers have functional groups on alternate different.
The structure of cis-1-bromor-2-butene is attached.
Generally, trans isomers are more stable than cis isomers..
Stable compounds have more negative heat of formation while unstable compounds have less negative heat of formation.
Therefore, the cis isomer will have a less negative heat of formation than the trans isomer.
Learn more about cis and trans isomers at: https://brainly.com/question/4625349
Please help asap! Giving brainliest to correct answer.
Three sections of the periodic table are labeled A, B, and C in the image below.
Which of the following statements is most likely true for an element present in section B?
Select one:
a. It is a highly reactive metal.
b. It is an inert gas at room temperature.
c. It may act as an insulator or a conductor.
d. It is a highly reactive liquid at room temperature.
Answer:
C. It may act as an insulator or a conductor.
Explanation:
Group B are the metalloids, so they have properties of both metals and nonmetals.
The statement which is most likely true for an element present in section B is: C. It may act as an insulator or a conductor.
A periodic table can be defined as an organized tabular array of all the chemical elements, which is typically arranged in order of increasing atomic number or number of protons (in rows).
In this diagram, the chemical element that is present in section B of the periodic table is a metalloid.
A metalloid can be defined as a chemical element that are typically intermediate between those of semiconductors, non-metals and metals.
Thus, a metalloid has both chemical and physical properties that are a combination of metals and non-metals or semiconductors.In this context, the statement which is most likely true for an element present in section B is that it may act as an insulator or a conductor because it is a metalloid.
Read more: https://brainly.com/question/17482288
A first order reaction has a rate constant of 0.924 at 25 oC. Given that the activation energy is 89.8 kJ/mol, calculate the rate constant at 33.3 oC.
Answer:
[tex]k_2=2.46[/tex]
Explanation:
Hello!
In this case, according to the Arrhenius equation for variable temperature:
[tex]ln(\frac{k_2}{k_1} )=-\frac{Ea}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]
Given the temperatures to be computed in kelvins and the activation energy, we obtain:
[tex]ln(\frac{k_2}{0.924} )=-\frac{89800J/mol}{8.314J/(mol*K)}(\frac{1}{306.45K} -\frac{1}{298.15K} )\\\\ln(\frac{k_2}{0.924} )=0.981\\\\k_2=0.924*exp(0.981)\\\\k_2=2.46[/tex]
Best regards!
You find yourself in a room with dark gray walls. Medeleev’s image says, “This element is essential for plant life to thrive and is found in heavy clay minerals and the ash from your campfire.” What element are these walls made from?
Answer:
juvn hgf jb ujvi i junk food sux
Explanation:
What is the density of an object that has a mass of 28.1g and a volume of 96.2mL? Select the correct answer below: 0.292g/mL 2703g/mL 1.00g/mL 3.42g/mL
Answer:
0.292 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density of an object is simply defined as the mass of the object per unit volume of the object. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the density of the object as follow:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density = mass / volume
Density = 28.1 / 96.2
Density of object = 0.292 g/mL
Thus the density of the object is 0.292 g/mL