Explanation:
1) Initial mass of the Cesium-137=
= 180 mg
Mass of Cesium after time t = N
Formula used :
Half life of the cesium-137 =
= initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope
= rate constant

Now put all the given values in this formula, we get
Mass that remains after t years.

Therefore, the parent isotope remain after one half life will be, 100 grams.
2)
t = 70 years


N = 35.73 mg
35.73 mg of cesium-137 will remain after 70 years.
3)


N = 1 mg
t = ?

t = 224.80 years ≈ 225 years
After 225 years only 1 mg of cesium-137 will remain.
There are ALOT because they would always come in and out and they will burst which creates more so techneclly there are infinate
Answer:
The correct option is;
It contains 6.02 × 10²³ particles of a given substance
Explanation:
A mole of substance is the standard scientific unit of measurement for the quantity of the substance which is made up of a large number of small particles such as molecules, ions, atoms, electrons or other entities.
The General Conference on Weights and Measures defines the mole as the amount of a substance that contains 6.02214076 × 10²³ units of entities
The number 6.02214076 × 10²³, is also known as Avogadro's number.
<span>thermal energy
hope this helped</span>
The name of the chemical made of 14 g Lithium or 2 moles
Lithium, 32 g Sulfur or 1 mol sulfur and 64 g oxygen or 4 moles of oxygen is
Lithium sulfate. From the chemical reation:
<span>2Li + S + 4O > Li2SO4</span>