Which of the following must be the same before and after a chemical reaction? a) the sum of the masses of all substances involved. b) the number of molecules of all substances involved. c) the number of atoms of each type involved. d) both (a) and (c) must be the same.

What creates an electric force field that moves electrons through a circuit? a. energy sourceb. loadc. metal wiresd. resistance

Arah is eating lunch with friends outside in the commons area of her school. one of sarah’s friends offers to share a marijuana joint with her. what could be the outcome if sarah were caught smoking marijuana at school? nothing will happen because she did not buy the joint. she could be suspended from school. nothing will happen because she is underage. the consequences would be up to sarah’s parents.

The average american baby will blank their birthweight by the time they turn one year-old