Answer:
2.3125g
Explanation:
Half-life referred to the time required for a quantity to reduce to half of its initial value, It used to calculate how unstable atoms undergo, or the period of time and atom can survive, radioactive decay.
Given:
t(1/2)= 9.25days
Initial mass of Thulium-167 = 48grams
We need to calculate the remaining amount after 37days.
Since we know that 1 half life = 9.25 days
Then 37 days means ( 37/9.25) half lives
37days means 4 half life
That means the 38grams of Thulium-167 will be halved by 4 times.
Then the ratio between the initial Amount and the amount remaining after 37 days can be calculated as. 0.5^(4)
= 37days × 0.5^(4)
= 2.3125g
the remaining amount of Thallium-167 after 37days is 2.3125g
It is exothermic and will have a negative enthalpy.
Answer:
Hydrogen
Explanation:
Hydrogen, most abundant in the universe, is the chemical element with atomic number 1, and an atomic mass of 1.00794 amu, the lightest of all known elements. It exists as a diatomic gas (H2).
Argon is the third most common gas found in the air we breathe. The air we breathe has approximately 78% nitrogen and 21 % oxygen. The third more abundant gas in the air we breathe is Argon. It is available in a very small quantity in the air that we breathe.
The percentage of the gas argon is about 0.9% in the air
that we breathe. There are several other gases also present in the air that we
breathe, but they are found mostly in negligible amounts.
