Please help a sample is in the second half life. what percent of the sample is stable at this point? 12.5%
25%
50%
75%

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

The diagram below shows the movement of particles. what does this piece of evidence best support? the collision theory the maxwell-boltzmann distribution the effect of pressure on reaction rates the effect of temperature on reaction rates