Cells can regulate different processes in two ways. They can turn on and off the genes that make enzymes, or they can

A)

increase the activation energy of a reaction.

B)

increase the amount of energy needed to carry out the preferred process.

C)

regulate the enzymes that are already made.

D)

decrease the amount of energy needed to carry out the preferred process.

Answer: A

Explanation:

i just took the quiz and it was right!

Answer:

here hope it helps

Explanation:

covalent bonds

From the formula of methane it is clear that one mole of methane has 4hydrogen atoms. So, 37.6×1023 hydrogen atoms are there in 25.0 g of methane. Therefore, 9.4×1023methane molecules and 9.4×1023 hydrogen and 37.6×1023carbon atoms are there in 25.0 g of methane.

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Explanation:

Melting is defined as the physical process where a solid state of a substance converts into its liquid state. No change of chemical composition takes place, just the physical state of water is changing.

[tex]\text{Solid}\rightleftharpoons \text{Liquid}[/tex]

There are given carboxylic acids. The melting point of these acids increases to its second group member which is ethanoic acid due to prevalent hydrogen bonding. To break this bonding, a high amount of heat needs to be applied.

But as we move forward, the melting point decreases sharply as an increase in the number of carbon atoms decreases the hydrogen bonding.

Melting point of Formic Acid = [tex]8.3^oC[/tex]

Melting point of Acetic Acid = [tex]16.6^oC[/tex]

Melting point of Propionic Acid = [tex]-21^oC[/tex]

When the amount of gas in a container is increased, the volume increases. Lussac's law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.

Answer:

B

Explanation:

Answer:

I think it's impure . Hope this helps you

Answer:

I think is pure but not 100% pure.

Answer:

As we know that alkalis react with oil to form soap. As our skin contains oil so when we touch strong alkalis, a reaction takes place and the soapy solution is formed. Hence we should wear gloves.

Answer:

As we know that alkalis react with oil to form soap. As our skin contains oil so when we touch strong alkalis, a reaction takes place and the soapy solution is formed. Hence we should wear gloves.

Explanation:

it from internet

Answer:

16mL

Explanation:

Using the following formula;

CaVa = CbVb

Where;

Where

Ca = concentration/molarity of acid (M)

Va = volume of acid (mL)

Cb = concentration/molarity of base (M)

Vb = volume of base (mL)

According to the information provided in this question;

Ca (HCl) = 2M

Cb (NaOH) = 5M

Va (HCl) = 40mL

Vb (NaOH) = ?

Using CaVa = CbVb

Vb = CaVa/Cb

Vb = 2 × 40/5

Vb = 80/5

Vb = 16mL

Answer:

As the kinetic energy of the gaseous solute increases, its molecules have a greater tendency to escape the attraction of the solvent molecules and return to the gas phase. Therefore, the solubility of a gas decreases as the temperature increases.

Explanation:

As the kinetic energy of the gaseous solute increases, its molecules have a greater tendency to escape the attraction of the solvent molecules and return to the gas phase. Therefore, the solubility of a gas decreases as the temperature increases

Answer:

Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.

Explanation:

The equation is balanced.

The number of P atoms in the reactant side is 4 and the number of P atoms in the product side is also 4.

The number of O atoms in the reactant side is 16 and the number of O atoms in the product side is also 16.

The number of H atoms in the reactant side is 12 and the number of H atoms in the product side is also 12.

These results are in accordance with the law of conservation of mass.

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Answer:

7

Explanation:

took test

Answer: 1) 400N

2)1.6

Explanation:

1) 5cm = 100N of force

so

20cm=400n

2) 0.4 X 4 = 1.6

Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.

Explanation:

According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.

Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.

[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]

Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.

Answer:

Nitrogen

Explanation:

According to the Periodic Table, the atom with a mass is 16 but the Atomic number is 7 for Nitrogen. That means that Nitrogen is an isotope.

Answer:

9

Explanation:

I took the same test :)

The stoichiometry is important in chemistry which helps us to use the balanced equation to calculate the amount of reactants and products. Here the moles of hydrogen needed is 9. The correct option is B.

The quantitative study of the reactants and products involved in a chemical reaction is known as the chemical stoichiometry. The stoichiometric coefficients can be fractions including the whole numbers.  It helps to establish the mole ratio.

The stoichiometric coefficient is basically the number which is present in front of the atoms, molecules or ions. The stoichiometric calculations are also used in gravimetry and volumetry.

Here the balanced equation for the reaction is:

N₂ + 3H₂ → 2NH₃

Number of moles of H₂ = 3 mol N₂× 3 mol H₂  / 1 mol N₂ = 9 mol H₂

So the number of moles of H₂ is 9.

Thus the correct option is B.

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Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.

Explanation:

A change that leads to the change in chemical composition of a substance is called a chemical change.

For example, [tex]2NH_{3} \rightarrow N_{2} + 3H_{2}[/tex]

Here, bond between the reactant atoms nitrogen and hydrogen is broken down.

On the other hand, bond connecting the products that is [tex]N_{2}[/tex] and [tex]H_{2}[/tex] is formed.

Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.

Answer:

the amount of trials in an experiment

Answer:

72.5Kg

Explanation:

that is the procedure above

Answer:

Lead can harm production of blood cells and the absorption of calcium needed for strong bones and teeth, muscle movements, and the work of nerves and blood vessels. High lead levels can cause brain and kidney damage.

thanks

Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones where it accumulates over time. Lead stored in bone may be remobilized into the blood during pregnancy, thus exposing the fetus.

Answer:

option no. C is correct

an electron in the 3d

The question is incomplete, the complete question is:

A curium-245 nucleus is hit with a neutron and changes as shown by the equation. Complete the equation by filling in the missing parts.

[tex]_{96}^{245}\textrm{Cm}+_0^1\textrm{n}\rightarrow _{42}^{103}\textrm{Mo}+_{r}^{q}\textrm{p}+3_0^1\textrm{n}[/tex]

Answer: The complete equation formed is [tex]_{96}^{245}\textrm{Cm}+_0^1\textrm{n}\rightarrow _{42}^{103}\textrm{Mo}+_{54}^{140}\textrm{Xe}+3_0^1\textrm{n}[/tex]

Explanation:

The general representation of an isotope is given as:

[rex]_Z^A\textrm{X}[/tex]

where,

A is the mass number, Z is the atomic number and X is the symbol of the element

In a nuclear reaction, total atomic number and total mass number on either side of the reaction remains the same

For the given chemical reaction:

[tex]_{96}^{245}\textrm{Cm}+_0^1\textrm{n}\rightarrow _{42}^{103}\textrm{Mo}+_{r}^{q}\textrm{p}+3_0^1\textrm{n}[/tex]

On the reactant side:

Total atomic number = [96 + 0] = 96

Total mass number = [245 + 1] = 246

On the product side:

Total atomic number = [42 + r + 0] = 42 + r

Total mass number = [103 + q + 3] = 106 + q

Calculating for 'r' and 'q', we get:

[tex]96= 42 + r\\\\r=96-42=54[/tex]

[tex]246 = 106+q\\\\q=246-106=140[/tex]

Thus, the missing isotope is [tex]_{54}^{140}\textrm{Xe}[/tex]

Hence, the complete equation formed is [tex]_{96}^{245}\textrm{Cm}+_0^1\textrm{n}\rightarrow _{42}^{103}\textrm{Mo}+_{54}^{140}\textrm{Xe}+3_0^1\textrm{n}[/tex]

Answer: try 140 52 xe

Explanation:

Answer:

may be the answer is Heat and pressure - melting - cooling

Answer:

Deposition

this is the process of a substance changing its state from gas to solid. Solid to gas is known as sublimation

Answer:

1/....

Explanation:

If we say acceleration 'a' is inversely proportional to mass 'm', then

a=1/m.

Answer:

use the prefix trans-

When naming a molecule, we indicate that the carbons on either side of the double bond are pointing in opposite directions by adding a prefix (-trans) in the name of the molecule.

IUPAC nomenclature of organic compounds refers to the systematic approach taken for the nomenclature of organic compounds as per the recommendation of the International Union of Pure and Applied Chemistry.

If alkenes have two different substituents at each end of the C=C then they can exist as stereoisomers (as geometric isomers).

This is because there is restricted rotation of the double bond due to the pi bond which means they don't readily interconvert.

Therefore, When naming a molecule, we indicate that the carbons on either side of the double bond are pointing in opposite directions by adding a prefix (-trans) in the name of the molecule.

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Answer:

Due to increase in carbondioxide gas.

Explanation:

The buffering action of these chemical reactions is limited by the present day rate of change for atmospheric carbondioxide concentration because the the rate of atmospheric carbondioxide rises as compared to ancient atmospheric carbondioxide gas. Due to increase of human activities, the concentration of carbondioxide gas increases in the atmosphere which limits the buffering action of these chemical reactions so we can say that carbondioxide gas is responsible for its limited action.

Answer: hello your question has some missing details attached below is the missing details

answer : 25.5%  ( B )

Explanation:

Determine percentage yield

molar mass = 35 g/mol

mass of Li₃N(s) = 70 g

product  LiH(s) = 8.0 g ( actual yield )

theoretical yield ( LiH ) =  4 * 7.95  = 31.8 g

percentage yield = actual yield * 100 / theoretical yield

                            = 8 * 100/31.8

                            = 25.5%