Which chemical reaction is most likely the slowest?
A. Red blood cells exchange oxygen molecules for carbon dioxide
molecules.
B. Oxygen produced by plants changes the pH of an aquarium's
water.
C. Chlorophyll in plants absorbs sunlight and converts it to chemical
energy
D. Rocks are eroded by acid rain.
Answer:
D
Explanation:
The chemical reaction is most likely the slowest will be rocks are eroded by acid rain.
What is chemical reaction?A chemical reaction occurs that involves the chemical change of one group of chemical compounds into another series of chemical substances.
What is acid rain?Acid rain was the rain that has an overabundance of acids.
The chemical reaction is most likely the slowest will be rocks are eroded by acid rain.
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Which element has seven energy levels?
rubidium (RD)
potassium (K)
cesium (Cs)
francium (Fr)
lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (FR) all have 7 energy levels
sorry if im wrong im kinda fried RN
Answer:
The answer is francium (Fr)
Explanation:
I just took the test
Juan lays an object on a table in a well-lighted room. The object absorbs all visible light waves. What color object does Juan see?
A. white
B. black
C. violet
D. red
I need the answer for science asap
Answer:
Black
Explanation:
White color reflects visible light while Black absorbs all light, and gives heat, so the answer is Black!
student carries out a titration to determine the concentration of a solution of
nitric acid. She titrates the solution of nitric acid against a standard solution
of sodium hydroxide with a known concentration of 0.0998 mol/dm². She
finds that 21.80 cm of the nitric acid solution is needed to exactly neutralise
25.0 cm of the sodium hydroxide solution.
Calculate the concentration of the nitric acid solution. Give your answer to
three significant figures.
The equation for the neutralisation reaction is
HNO3 + NaOH → NaNO3 + H2O
The concentration of the Nitric acid solution : 0.114 M
Further explanationTitration is a procedure for determining the concentration of a solution (analyte) by reacting with another solution whose known concentration (usually a standard solution) is called the titrant. Determination of the endpoint/equivalence point of the reaction can use indicators according to the appropriate pH range
Titrations can be acid-base titration, depositional titration, and redox titration. An acid-base titration is the principle of neutralization of acids and bases
Reaction
HNO₃ + NaOH → NaNO₃ + H₂O
Concentration a standard solution of sodium hydroxide : 0.0998 mol/dm³ , and the volume = 25 cm³
moles NaOH=
[tex]\tt mol=M\times V\\\\mol=0.0998\times 25\\\\mol=2.495~mlmoles[/tex]
From the equation, mol ratio HNO₃ : NaOH = 1 : 1, so mol HNO₃ = mol NaOH=2.495 mlmoles
The volume of HNO₃ = 21.8 cm³, so the concentration :
[tex]\tt M=\dfrac{n}{V}\\\\M=\dfrac{2.495}{21.8}\\\\M=0.114[/tex]
The concentration of the nitric acid solution is 0.11445 mol/dm³
From the question,
We are to calculate the concentration of the nitric acid solution
The given balanced chemical equation for the reaction is
HNO₃ + NaOH → NaNO₃ + H₂O
This means 1 mole of HNO₃ is needed to completely neutralize 1 mole of NaOH
Using the formula
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B}} = \frac{n_{A}}{n_{B}}[/tex]
Where [tex]C_{A}[/tex] is the concentration of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{A}[/tex] is the volume of acid
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
From the given information
[tex]C_{B}= 0.0998\ mol/dm^{3}[/tex]
[tex]V_{A} = 21.80 \ cm^{3}[/tex]
[tex]V_{B} = 25.0 \ cm^{3}[/tex]
From the balanced chemical equation
[tex]n_{A} = 1[/tex]
[tex]n_{B} =1[/tex]
Putting the parameters into the formula, we get
[tex]\frac{C_{A} \times 21.80 }{0.0998 \times 25.0} = \frac{1}{1}[/tex]
Then,
[tex]C_{A} \times 21.80=0.0998 \times 25.0[/tex]
∴ [tex]C_{A}=\frac{0.0998 \times 25.0}{21.80}[/tex]
[tex]C_{A} =\frac{2.495}{21.80}[/tex]
[tex]C_{A} = 0.11445 \ mol/dm^{3}[/tex]
Hence, the concentration of the nitric acid solution is 0.11445 mol/dm³
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Taking deep breaths can help trigger our
parasympathetic
system. The
parasympathetic nervous
system controls the regular functions like—————
Answer:
digestion
Explanation:
The parasympathetic nervous regulates life-sustaining processes, like digestion, during times when your body is relaxed.
how do you calculate the number of neutrons???? please help
Answer:
The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).
Explanation:
HOPE THIS HELP
PICK ME AS THE BRAINLIEST
What happens in cellular respiration?
A. Glucose reacts with water in the stomach to produce
energy.
B. Glucose and oxygen react to form carbon dioxide, water,
and heat.
O C. Glucose is broken down to provide oxygen for all cells in
the body.
D. Glucose is formed from smaller hydrocarbons in the body.
Answer:
Option B
Explanation:
The reaction can be summarized as
6O2+C6H12O6——›6CO2+6H2O+Heat
Answer:
B
Explanation:
On December 25th, 1776, General George Washington’s Continental Army crossed the Delaware River and defeated troops of Hessians (German soldiers fighting for the British). Here’s a fictionalized account of that historical event: “While our general stood bravely in the Christmas Day cold, I shivered from more than just the icy wind. Beyond the river were enemy soldiers from the most obscure corners of Europe. I could barely fathom the unknown monsters ahead.” How did the fiction author make the factual account more exciting? A The author altered the chronology of the historical events. B The author omitted the factual details, because readers already know them. C The author enhanced the drama by altering the description of the enemy troops. D The author created a sense of danger by changing the setting of the event.
Answer:the answer is C
Answer:
C
Explanation:
I'm doing this test now and I just got it right :)
1-10 balancing reactions
PLEASE HELP :))
HELP PLEASE
How can you tell for sure that a redox reaction has happened?
O A. If a precipitate forms, it is a redox reaction.
O B. If compounds break apart, it is a redox reaction.
O c. If atoms rearrange, it is a redox reaction.
O D. If oxidation states change, it is a redox reaction.
Answer:
Answer is D. Just took the quiz on A P E X
Explanation:
If oxidation states change, it is a redox reaction. Hence, option D is correct.
What are oxidation-reduction reactions?Oxidation-reduction reactions are balanced by two half overall chemical equations into an oxidation equation and a reduction equation.
In redox reactions, the half-reactions of oxidation and reduction always occur simultaneously in pairs.
The oxidation half-reaction involved the loss of electrons from a reduced substance (A) to form an oxidized substance (A⁺):
A ⇒ A⁺ + e-
In contraposition, during the reduction half-reaction the oxidized substance (B⁺) gains electrons to form the reduced substance (B):
B⁺ + e- ⇒ B
The overall redox reaction is obtained by the addition of the two half-reactions:
A ⇒ A⁺ + e-
B⁺ + e- ⇒ B
A + B⁺⇒ A⁺ + B
The electrons gained by B are provided by A, which lost the same number of electrons. Thus, the oxidation/reduction reactions are paired.
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what is the answer to this question
Answer:
(A)
Explanation:
It decreases cuz when they start climbing a mountain there air pressure is getting low and so is their blood. The higher they go the more it decreases. Hope this helps:)!
A meniscus must be considered when making which of the following measurements?
Answer:
When you read a scale on the side of a container with a meniscus, such as a graduated cylinder or volumetric flask, it's important that the measurement accounts for the meniscus. Measure so that the line you are reading is even with the center of the meniscus. For water and most liquids, this is the bottom of the meniscus. For mercury, take the measurement from the top of the meniscus. In either case, you are measuring based on the center of the meniscus. For a flat meniscus, make sure the liquid is level. Usually placing the container on a lab bench does the trick.
You won't be able to take an accurate reading looking up at the liquid level or down into it. Get eye level with the meniscus. You can either pick up the glassware to bring it to your level or else bend down to take measurements in situations where you're concerned with dropping the container or spilling its contents.
Use the same method to take measurements each time so that any errors you make will be consistent.
Explanation:
an unknown substance with a mass of 56.5 grams is placed in a graduated cylinder. what is the identity of the unknown substance? responses aluminum gold iron lead
56.5 grams of an unidentified material are put in a graduated cylinder. Lead is the name of the unknown material.
What is graduated cylinder?In order to make them lighter and less fragile than glass, large graded cylinders are typically manufactured of polypropylene due to its good chemical resistance or poly methyl pentene due to its transparency. Polypropylene (PP) is simple to repeatedly autoclave; however, autoclaving beyond 121 °C (250 °F) will warp or break polypropylene graduated cylinders, reducing accuracy (depending on the chemical composition; normal commercial grade polypropylene melts above 177 °C (351 °F)).
In order to improve the precision and accuracy of volume measurement, traditional graduated cylinders are typically tall and narrow. It has a "spout" for simple pouring of the measured liquid and a glass or plastic base (stand, foot, support). Another variation is low and wide.
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which two senses require that chemical compounds be dissolved in solution before they can act as stimulants for these senses?
The two senses which is require in the chemical compounds be dissolved in solution before they can act as stimulants for these senses are smell and odour.
Stimulant for smell include molecules which are dissolved in the air gas easily, can be easily detected by the odour recepters which are located on the nostrils upon binding. The smell neurons transfer this information to the smell bulb which are located in the forebrain all the olfactory process occur.
The sensation of taste occur when our food is dissolved in the saliva secreted by the salivary gland located below the tongue. This food dissolved in saliva binds with the recepters of the tongue which are located on the taste buds of papillae.
Thus, we concluded that the two senses which is require in the chemical compounds be dissolved in solution before they can act as stimulants for these senses are smell and odour.
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HOW MANY MILLILITERS ARE IN 98.1 M? WHAT IS THE UNIT?
Answer:98.1 meters = 98,100 mm
Explanation: 1 meter = 1,000 mm.
The boiling point of a pure substance is defined as the temperature at which
Explanation:
The boiling point of a pure substance is the temperature at which the substance transitions from a liquid to the gaseous phase. At this point, the vapor pressure of the liquid is equal to the applied pressure on the liquid.
please help find the significant figure when the mass is converted to mg
Which element, (O) (F), has a smaller atomic radius?
Florine has a smaller atomic radius than oxygen
Atomic radius or Atomic Radii is the total distance from the nucleus of an atom to the outermost orbital of its electron and in the given element oxygen and Florine, Florine has the smallest atomic radius because in moving from left to right across a period, the atomic radius decreases as the effective nuclear charge increases and because of greater positive charge of the nucleus, pulling electron and electron shell in closer. therefore, the Florine has smallest atomic radius than oxygen atomic radii of oxygen is 48pm.
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The model of the atom changed as new evidence was discovered. The plum pudding model suggested that the atom was a ball of positive charge with electrons embedded in it. Evidence from the alpha particle scattering experiment led to a change in the model of the atom from the plum pudding model. Explain how. PLS HELP RN :)
Answer:
so since the model atom was changed as new evidence, and the plum pudding model was a ball of positive charge, the alpha particle scattering which broke up the atom
Use the Venn Diagram below to identify where the listed characteristics belong.
The atom's nucleus is composed of neutrons and protons. BOTH: In the nucleus. Contribute to the mass of the atom. Mass equal 1 amu. PROTON. Number is atomic number of element. Determine the identity of the atom. NEUTRON: Neutral charge.
What is a subatomic particle?
Subatomic particles are matter structures that are smaller in size than an atom. Hence, subatomic particles compose the atoms, determining their properties.
Many subatomic particles are unstable and remain unknown. However, three of them are the most stable ones,
protons electronsneutronsSubatomic particles can be either,
compound ⇒ divisible ⇒ protons and neutronelementary ⇒indivisible ⇒ electronsNeutrons and protons compose the nucleus of the atoms, while electrons orbit around them.
These particles differ in their electric charge and their mass.
Protons have a positive charge (+)Neutrons have no charge (0)Electrons have a negative charge (-)
The number of protons in the atom is the atomic number and determines the atom's identity.
The massic number is the addition of the number of protons and the number of neutrons.
Atomic mass is composed of neutrons and protons mass. It is not the same as the massic number or the atomic weight.
When protons, neutrons, and electrons get together to form an atom, they lose part of their mass as energy. This is why the atomic weight is slightly inferior to the sum of masses.
1) BOTH
In the nucleus
Contribute to the mass of the atom
Mass equal 1 amu (1.67377 x 10⁻²⁷ kg or 1.67377 x 10⁻²⁴ g)
2) PROTON
Number is atomic number of element
Determine the identity of the atom
3) NEUTRON
Neutral charge
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Is the Food Pyramid important to Humans and our Digestive Systems? Explain why or why not below please use a complete sentence, or put what the one thing that we cannot digest but is in the food pyramid.
Answer:
The food pyramid is just to make people have a healthier "Diet."
Explanation:
It shows the food groups we eat and which ones to put together to make a healthy diet. Eating the right amount of each food group is called a "Balance" diet. Therefore, its not needed, but it is useful.
The prophet Isaac was chosen to lead the Israelites after the death of Abraham.
O True
O False
How many moles of NaCl are in a 1 kg salt packet? Write the answer to one decimal place.
1Kg = 1000g
the molar mass of NaCl = 58.44 g/mol
number of moles = Mass / Molar mass
n = 1000g ÷ (58.44 g/mol)
n = 17.1115 mol
since you want the answer in one decimal place
then number of moles = 17.1 moles
Consider this reaction: Upper K Upper O Upper H + Upper H Upper B 4 right arrow Upper K Upper B r + Upper H Subscript 2 Baseline Upper O
Which is the acid in this reaction?
KOH
HBr
KBr
H2O
Answer:
HBr
Explanation:
. the density (d) of a substance is an intensive property that is defined as the ratio of its mass (m) to its volume (v). density
Density is intensive because it is the ratio of two extensive properties that is mass to volume.
What is Density ?Density is defined as mass per unit volume. S.I unit if density is kg/m³.
It is expressed as
Density = [tex]\frac{\text{Mass}}{\text{Volume}}[/tex] or [tex]d = \frac{m}{V}[/tex]
What is Intensive Property ?Intensive property is the property which does not depend on the size of the system. Intensive property can be easily identified. Intensive property is the independent property. The size does not change in this.
Example of intensive property are Density, Freezing point, melting point, colour, Lustre, etc.
What is Extensive property ?Extensive property is the property which depend on the substance. Extensive property cannot be easily identified.
Example of extensive property length, weight, volume, mass etc.
Thus from the above conclusion we can say that Density is intensive because it is the ratio of two extensive properties that is mass to volume.
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Disclaimer: The given question is incomplete on the portal. Here is the complete question.
Question: The density (d) of a substance is an intensive property that is defined as the ratio of its mass (m) to its volume (v)
density = [tex]\frac{\text{Mass}}{\text{Volume}}[/tex] or [tex]d = \frac{m}{V}[/tex]
Considering that mass and volume are both extensive properties, explain why their ratio, density is intensive.
which of the following instruments id used to describe how much matter is an object
Answer:
Mass measures the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg). Volume measures the amount of space that a substance or an object takes up.
Hope it help
Where would crystals form beneath the surface
All of these happen beneath the surface
lava cooling
evaporation of a solution
hot water solutions
The word science means...
Life
Knowledge
Thinking
By definition science is, the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
A container of gas is initially at 0.25 atm and 0 ˚C. What will the pressure be at 125 ˚C?
Answer:
0.37atm
Explanation:
Given parameters:
Initial pressure = 0.25atm
Initial temperature = 0°C = 273K
Final temperature = 125°C = 125 + 273 = 398K
Unknown:
Final pressure = ?
Solution:
To solve this problem, we use a derivative of the combined gas law;
[tex]\frac{P1}{T1}[/tex] = [tex]\frac{P2}{T2}[/tex]
P and T are pressure and temperature
1 and 2 are initial and final values
[tex]\frac{0.25}{273}[/tex] = [tex]\frac{P2}{398}[/tex]
P2 = 0.37atm
What causes tectonic plates to move? What is a convergent boundary? What is a divergent boundary? What is a transform boundary? What is a transform boundary?
A transform boundary occurs when two tectonic plates move past one another.
What causes tectonic plates to move? What is a convergent boundary? What is a divergent boundary? What is a transform boundary? What is a transform boundary?
Tectonic Plates Movement:
The tectonic plates can be thought like the pieces of the broken or cracked shells. The heat from radioactive processes within the planet's interior causes the plates to move, The heat from radioactive processes within the planet's interior causes the movement of the tectonic plates.
Convergent Boundary:
Convergent boundary is that area or is that boundary from which the plates moves towards each other.
Divergent Boundary:
Divergent boundary is that boundary or area from which the tectonic plates starts moving away from each other.
Transform boundary:
The transform boundary is that boundary which causes a fault or error between the tectonic plates.
So we can conclude that a transform boundary occurs when two tectonic plates move past one another.
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