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2 years ago

What is radioactive dating in chemistry? PLEASE HELP!!!

1 answer:

7 0

Radioactive dating uses the concept of half life to determine the age of something.
The general idea is that elements exist naturally as a combination of isotopes. Some isotopes are stable while others decay radioactively. The half-life of a radioactive isotope is the time required to reduce the initial quantity of the isotope by 50% through the process of radioactive decay.
Carbon 14 dating works this way. A tree growing in the past would have an equilibrium mixture of C-12 and C-14 atoms in proportions consistent with living matter today. We know this value.
When that tree dies, it no longer accumulates new carbon atoms from carbon dioxide in the atmosphere (through photosynthesis). At this point, the proportion of C-14 in the organic matter that was the tree decreases due to the decay of C-14 to an isotope of nitrogen.
When we dig up the remnants of the tree today, we can measure the proportion of C-14 to C-12 and see how much it has been reduced. From this we can calculate backwards using the half life of C-14 (5730 years) to estimate how old the remains of the tree are.

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Most protein enzymes catalyze only one specific chemical reaction effectively. What feature of protein structure is most directl

babunello [35]

Answer;

d. the specific geometry and types of amino acids in the active site

Explanation;

-Enzymes are highly selective catalysts, meaning that each enzyme only speeds up a specific reaction. The molecules that an enzyme works with are called substrates. The substrates bind to a region on the enzyme called the active site.

-For a substrate to bind to the active site of an enzyme it must fit in the active site and be chemically attracted to it. The shape of an enzyme determines how it works. Enzymes have active sites that substrate molecules (the substances involved in the chemical reaction) fit into when a reaction happens.

8 0

3 years ago

How many electrons would be found in the Ion who’s symbol is I-

Vesnalui [34]

Answer:

Explanation:

Given symbol of the element:

I⁻

Number of electrons found in an ion with the symbol:

This is a iodine ion:

For an atom of iodine:

Electrons = 53

Protons = 53

Neutrons = 74

An ion of iodine is one that has lost or gained electrons.

For this one, we have a negatively charged ion which implies that the number of electrons is 1 more than that of the protons.

So, number of electrons = 53 + 1 = 54

The number of electrons in this ion is 54

6 0

2 years ago

If a solution contains 3 moles/liter of sodium chloride (nacl, made of sodium ions and chloride ions), what is the osmolarity of

valkas [14]

<u>Answer:</u> Osmolarity of the sodium chloride solution is 18 Osmol/L.

<u>Explanation:</u>

Osmolarity is defined as the the concentration of the solution which is expressed as the total number of solution particles present in one liter of solvent.

We are given the molarity of the solution which is 3mol/L and to convert it into osmolarity, we will multiply the number of osmoles that are produced by the solute.

Osmole is defined as the particles that contribute to the osmotic pressure of a solution.

The solute given here is sodium chloride (NaCl). Number of osmoles can be determined by the dissociation of this solvent into ions.

The equation given by the dissociation of NaCl:

$NaCl\rightarrow Na^++Cl^-$

1 mole of sodium chloride produces 2 moles of ions.

So, 3 moles of sodium chloride will produce = (3 × 2) = 6 moles of ions.

Hence, osmolarity of the sodium chloride solution will be $6\times 3mol/L=18Osmol/L$

5 0

2 years ago

Explain what air is, where on Earth it occurs, and how it moves to create wind.

pickupchik [31]

Answer:

Wind is caused by differences of pressure in the Earth's atmosphere. Air from a high pressure area will move towards an area of low pressure. High winds are caused when air moves between areas with large differences in air pressure.

Explanation:

4 0

3 years ago

4.50 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 1

Anna11 [10]

Answer:

$\mathbf{C_{10}H_8}$ ( Naphthalene )

Explanation:

Given that:

4.50 g of a Compound X is made up of Carbon , Hydron and Oxygen

It's molecular molar mass = 128 g/mol

Compound X undergoes combustion reaction and the product yield :

CO_2 with mass 15.47g and :

H_2O with mass 2.53 g

The objective is to use this information to determine the molecular formula of X.

We all know that ; number of moles = mass/molar mass

where the molar mass of H_2O is 18 g/mol

number of moles of H_2O product = 2.53 g/18 g/mol

number of moles of H_2O product = 0.1406 moles

Also; the molar mass of CO_2 product = 44 g/mol

number of moles of CO_2 product = 15.47g/ 44 g/mol

number of moles of CO_2 product = 0.3516 moles

number of moles of Compound X in the reactant side= 4.50 g /128 g/mol

number of moles of Compound X n the reactant side= 0.03516 moles

Now; number number of moles of CO_2 in reactant = 0.3516 moles/0.03516 moles

Now; number number of moles of CO_2 in reactant = 10

number of moles of H_2O reactant = 0.1406 moles × 2/0.03516

number of moles of H_2O reactant = 7.997 ≅ 8

Since we said the Compound X is known to be made of Carbon C , Hydrogen H and Oxygen O

Then the molecular formula can be written as :

$\mathbf{C_{10}H_8O_{x}}$

In order to find the x; we have

128 = (12 × 10 + 1 × 8 + 16 × x)

128 = 120 + 8 + 16x)

128 = 128 + 16 x

128 - 128 = 16 x

0 = 16 x

x = 0/16

x = 0

As x = 0 ; hence there are no oxygen present in the reaction

Thus; the molecular formula of Compound X = $\mathbf{C_{10}H_8}$ which is also known as Naphthalene

5 0

3 years ago