If an atom has 17 protons, 18 neutrons, and 17 electrons, what is the mass of this atom?
a: 17
b: 18
c: 35
d: 52

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Why do lunar and solar eclipse not happen every month

An unknown insoluble substance displaced the water shown. it's mass is indicated on the triple beam balance. mass = a. 694 b. 693.5 c. 693.0 d.693.8