NEED ANSWERED ASAP WILL GIVE BRAINIEST!!

if a material has a radioactivity level of 100 curies and has a half-life of 10 years, how many half lives will have occurred after 100 years?

i think its 5 but im only in 7th grade so heh but im pretty sure

pretty surrExplanation:

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands