Answer:
3 years
Explanation:
Given data:
Initial amount of sample = 160 Kg
Amount left after 12 years = 10 Kg
Half life = ?
Solution:
at time zero = 160 Kg
1st half life = 160/2 = 80 kg
2nd half life = 80/2 = 40 kg
3rd half life = 40 / 2 = 20 kg
4th half life = 20 / 2 = 10 kg
Half life:
HL = elapsed time / half life
12 years / 4 = 3 years
<h3>
Answer:</h3>
0.144 moles
<h3>
Explanation:</h3>
- The relationship between mass of a compound, number of moles and molar mass of the compound is given by;
- Number of moles = Mass ÷ Molar mass
- Molar mass is equivalent to the relative formula mass of the compound that is calculated the atomic masses of the elements making the compound.
In this case;
Our compound, KClO3 will have a molar mass of;
= 39 + 35.5 + 4(16)
= 138.5 g/mol
Mass of KClO3 is 20 g
Therefore;
Number of moles = 20 g ÷ 138.5 g/mol
= 0.144 moles
Thus, the number of moles in 20 g of KClO3 is 0.144 moles
2 is right am 70 percent sure
Answer:
There are 
grams contained in all the seawater in the world.
Explanation:
At first let is determinate the total mass of seawater (
), measured in grams, in the world by definition of density and considering that mass is distributed uniformly:
Where:
- Density of seawater, measured in grams per liters.
- Volume of seawater, measured in liters.
If 
and 
, then:
The total mass of sodium chloride is determined by the following ratio:
Given that and 
, the total mass of sodium chloride in all the seawater in the world is:
There are grams contained in all the seawater in the world.
Hydrocarbons are carbon and hydrogen. Methane is CH4, and propane is C3H8. Methene is CH3, and propene is C3H6. Carbohydrates are hydrates of carbon. They <span>have the general formula (CH2O)x. thats how it differs
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