Periodic Table of the Elements Crossword

The smallest unit of an element that maintains the properties of that element.
A subatomic particle that has a negative charge.
In physical science, an atom's central region, which is made up of protons and neutrons.
The region around the nucleus of an atom where electrons are likely to be found.
The subatomic particle that has a positive charge and that is found in the nucleus.
The unit of mass that describes the mass of an atom.
The subatomic particle that has no charge and that is found in the nucleus of an atom.
The number of protons in the nucleus of an atom.
An atom that has the same number of protons as other atoms of the same element have.
The sum of the number of protons and neutrons in the nucleus of an atom.
The mass of an atom expressed in atomic mass units.
The charge of an electron.
The charge of a proton.
The force that holds electrons in atoms.
The Greek philosopher who proposed that small particles called atoms make up all matter.
The German chemist who discovered the element Phosphorus.
This man is largely regarded today as the first modern chemist.
The Periodic Table of the Elements is arranged in horizontal rows called this.
The Periodic Table of the Elements is arranged in vertical columns called this.
When two or more elements are chemically combined together.
When two or more atoms are joined together.
A substance made entirely from one type of atom.