Answer:
3.59x10^21 molecules
Explanation:
1mole of a substance contains 6.02x10^23 molecules.
Therefore, 1mole of C8H18 will also contain 6.02x10^23 molecules
1mole of C8H18 = (12x8) +(18x1) = 96 + 18 = 114g.
1mole (i.e 114g) oh C8H18 contains 6.02x10^23 molecules.
Therefore, 0.68g of C8H18 will contain = (0.68 x 6.02x10^23)/114 = 3.59x10^21 molecules
There are 66 neutrons in a single atom of indium-115. The atomic number of indium-115 is 49, meaning there are 49 protons. Then the atomic mass is 115, so 115-49 = 66.
Answer:
33300J
Explanation:
Given parameters:
Mass of ice = 100g
Unknown:
Amount of energy = ?
Solution:
This is a phase change process from solid to liquid. In this case, the latent heat of melting of ice is 3.33 x 10⁵ J/kg.
So;
H = mL
m is the mass
L is the latent heat of melting ice
Now, insert the parameters and solve;
H = mL
mass from gram to kilogram;
100g gives 0.1kg
H = 0.1 x 3.33 x 10⁵ = 33300J
Thallium has got 81 protons
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