Which of the following has a positive charge?

The neutral atoms of all of the isotopes of the same element have

A subatomic particle that has a negative charge is called a(n)

What is an atom's nucleus made of?

An element's atomic number is equal to its number of 

What is the mass number of an element that has 19 protons, 19 electrons, and 20 neutrons?

The central core of an atom is called the nucleus.

Two elements with the same number of protons, but a different number of neutrons are called ____________.

How many protons, neutrons, and electrons are in the atom ²⁵₁₂Mg?

How many protons, neutrons, and electrons are in the ion represented by the symbol ²⁷₁₃Al⁺³ ?