An alpha particle is closest in atomic mass to which element?
a. h
b. he
c. ne
d. xe

Ted and emily played a mixed doubles tennis match against jack and brenda. in the second match. ted and brenda played against jack and emily. which type of chemical reaction does the situation demonstrate?

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

Which characteristics can be used to differentiate star systems? check all that apply.