Explanation:
It is known that in a simple cubic unit cell the atoms are only present at the corner of the unit cell. This means that there are in total 8 atoms present in a simple cubic unit cell.
Therefore, in one simple cubic unit cell sharing of one atom is only 
.
Hence, the total number of atoms in a unit cell will be as follows.
= 1
Thus, we can conclude that there is 1 calcium atom present in each unit cell.
Answer:
b. 17,190
Explanation:
Using the formula for C-14 dating,
where Present Value N =1/8 of Parent Sample
Initial Value, 
=1
Half Life, 
=5730 years
=17,190
Therefore the fossil is about 17190 years old.
B
Explanation:
Burning is a chemical change and cutting grass is a physical change
Answer:
0.18× 10²³ molecules
Explanation:
Given data:
Mass of copper hydroxide = 3.30 g
Number of molecules = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 3.30 g/97.56 g/mol
Number of moles = 0.03 mol
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
0.03 mol × 6.022 × 10²³ molecules / 1mol
0.18× 10²³ molecules
We know that
pH = -log[H+]
the pH value falls in between 0- 7 for acids
As the pH value increases the concentration of [H+] increases.
similarly as the value of pH approaches 0, the concentration of H+ increases
The solution said to become more acidic
Also
[H+] X [OH-] = 10^-14
Thus pH + pOH = 14
hence the concentration of OH- decreases as the pH approaches zero
