Sloan Science 8-Atoms

Element

Matter made up of only one kind of atom. Elements are pure substances. Example: Oxygen (O), Lithium (Li). SENTENCE: The periodic table of elements gives information about all the different types of elements.

Subatomic Particles

Protons, Neutrons, or Electrons. The small particles within an atom. SENTENCE: The word subatomic means smaller than an atom.

Nucleus

The central part of an atom, made up of protons and neutrons. SENTENCE: All atoms have a nucleus in the center.

Electron

The negatively charged subatomic particle located outside of the nucleus in levels/shells. SENTENCE: The electrons are tiny particles that orbit around the nucleus of an atom.

Neutron

The neutrally charged subatomic particle located inside the nucleus of an atom. SENTENCE: A neutron has the same size, mass, and location in the nucleus as a proton.

Proton

The positively charged subatomic particle located inside the nucleus of an atom. SENTENCE: The number of protons in an atom is the same as its atomic number.

Atom

The smallest particle of an element that still has the properties of the element. SENTENCE: All matter is made up of atoms.

Mass Number

the average mass of an atom of an element SENTENCE: The mass number of an element allows us to calculate the number of neutrons in the nucleus of an atom.

Atomic Number

the number of protons in the nucleus of an element; the top number in the periodic table SENTENCE: The atomic number of an element equals the number of protons and equals the number of electrons in an atom.

Molecule

two or more atoms bonded (joined) together SENTENCE: Water is made of molecules formed when two hydrogen atoms and one oxygen atom bond together.