I needed more help on my assignment soo

1. Our bodies exhale carbon dioxide (CO 2 ). Carbon dioxide . (more than one answer)
A.) is a compound
B.) has two atoms of oxygen
C.) is made of oxygen and carbon
D.) is an element
E.) has two molecules of oxygen
2. Atomic mass is calculated by adding(protons, electrons, OR isotopes) and(molecules, protons, OR neutrons).
3. The chemical formula for magnesium oxide is 2MgO. The number 2 represents the number of ___.
A.) oxygen atoms
B.)magnesium atoms
C.)magnesium oxide molecules

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

One of the few xenon compounds that form is cesium xenon heptafluoride (csxef7). how many moles of csxef7 can be produced from the reaction of 13.0 mol cesium fluoride with 12.5 mol xenon hexafluoride? csf(s) + xef6(s) csxef7(s)

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.