Atomic and mass numbers

What is the mass number of this atom?

An element has the mass number 12 and atomic number 6. The number of neutrons in it is:

If an atom has 10 electrons, how many protons does it have?

Anything that has mass and takes up space

equal to the number of protons plus neutrons in the nucleus of an atom

Which of the following states of matter has a definite volume and a definite shape?

Which state of matter takes the shape of the container that it is in?