The atmosphere is primarily made of what gas? Carbon Dioxide
Nitrogen
Oxygen
Argon​

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

98 ! and brainliest plz ! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg