1. The atomic number of an element is determined by the number of:
a. protons.
b. electrons.
C. neutrons.
d. isotopes.

Aweight lifter raises a 1600 n barbell to a height of 2.0 meters. how much work was done? w = fd a) 30 joules b) 3000 joules c) 320 joules d) 3200 joules

How many grams are in 68.2 molecules of br2?

How many significant figures are in the following numbers ? a. 0.0002030 b. 2.000 c. 2.008900 d. 145.00