Answer: there are three different methods of determining the age of a landform.
1 radiation measurement
2 stratigraphic superposition
3 the fossil record
by using these or a combination of these they determined that the earth is around 4.6 billion years old. and this is where the big bang theory comes into play.
The number of mole of copper in the sample is 0.008 mole.
Mole is simply defined as the unit of amount in a substance.
The mole of a substance can be obtained by dividing the mass of the subtance by its molar mass i.e
Mole = mass / molar mass
With the above information, we can obtain the mole of copper in the compound as follow:
Mass of copper = 0.5066 g
Molar mass of copper = 63.5 g/mol
<h3>Mole of copper =? </h3>
Mole = mass / molar mass
Mole of copper = 0.5066 / 63.5
<h3>Mole of copper = 0.008 mole </h3>
Therefore, 0.008 mole of copper was initially present in the compound.
Learn more: brainly.com/question/14295066
Answer: 
Explanation: A double displacement reaction is one in which exchange of ions take place.
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 answer is <span>1.63 × 1024 atoms Fe.
</span>
Avogadro's number is the
number of units (atoms, molecules) in 1 mole of substance:
<span>6.023 × 10²³ atoms per 1 mole
</span>So, how many atoms are per 2.70 moles:
6.023 × 10²³ atoms : 1 mole = x : 2.70 moles
x = 6.023 × 10²³ atoms * 2.70 moles : 1 mole
x = 16.3 × 10²³ = 1.63 × 10 × 10²³ = 1.63 × 10²⁴ atoms
