Use the ideal gas law:
PV = nRT
so, T = PV / nR
n=0.5
V= 120 dm^3 = 120 L (1 dm^3 = 1 L)
R = 1/12
P = 15,000 Pa = 0.147 atm (1 pa = 9.86 10^{-6} )
Put the values:
T = PV / nR
T = (0.147) (120) / (0.5) (1/12)
T= 426 K
For the first one, you have to find one that has both a metal and a nonmetal in it, plus potassium. Bonds between nonmetals are called covalent because they share electrons and a bond between a metal and a nonmetal is an ionic bond because they exchange electrons.
Potassium chloride is KCl. Only an ionic bond.
Potassium hydride is KH. Only an ionic bond.
Potassium nitrate is KNO3. There we go, that has a covalent bond between the nitrogen and oxygen, and an ionic bond between potassium and the nitrogen and oxygen.
For the second one, potassium chloride is the answer because the other three also have covalent bonds. Chloride is the only one that isn't a compound.
Hey there! The answer to your first question is SILICON, Nickle has 28 protons, silicon has 14, 14+14=28. Its the only element thats adds up. I dont know about the 2nd one myself.
When Iodine-131 emits a β particle will produce Xe-131
<h3>Further explanation
</h3>
Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
- alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles ₀γ⁰
- positron particles ₁e⁰
- neutron ₀n¹
So for reaction Iodine-131 :

Answer:
Absorb light energy
Explanation:
Chlorophyll absorbs light energy which is used to produce carbohydrate and oxygen in the presence of carbon dioxide and water.