fast and explain how to solve half life

a 208 grams sample of sodium-24 decays to 52 grams in 30 hours. what is the half-life
of this radioactive sample?

Consider the balanced equation below. n2h4 + 2h2o2 n2 + 4h2o what are the mole ratios of hydrazine (n2h4) to hydrogen peroxide (h2o2) and hydrazine to water? 1: 2 and 1: 4 1: 3 and 1: 4 1: 2 and 3: 5 1: 3 and 3: 5

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

In 2002, the rare earth elements mine in mountain pass, california was closed because