Can someone please help I will mark u brainliest (PLEASE IT¨S URGENT)

Flourine is found to undergo 10% radioactivity decay in 366 minutes determine its halflife

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

Maya wrote if you step to describe how carbon circulates between the atmosphere and living organisms