Which of the following leads to a higher rate of effusion?

a. cooler gas sample
b. lower molar mass
c. slower particle movement
d. reduced temperature

b. Lower molar mass.

Explanation:

∨ ∝ 1/√M.

where, ∨ is the rate of diffusion of the gas.

M is the molar mass of the gas.

As the gas has a lower molar mass, it will have a higher rate of effusion.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.