What is the periodic table?
Two or more atoms chemically combined.
What is a molecule?
The 3 particles that make up an atom.
What are protons, neutrons and electrons?
The number of these in the nucleus change to make an isotope of an atom.
What are neutrons?
They determine if the atom has a positive or negative charge.
What are (valence) electrons?
The first element on the periodic table.
What is Hydrogen?
A pure substance made up of one type of atom.
What is an element?
They have a negative charge.
What are electrons?
The number we look at to determine whether an atom is an isotope.
What is the atomic mass?
The name for the outermost electrons of an atom.
What are valence electrons?
Where most of the atom's mass/weight is found.
What is the nucleus?
When two or more elements are in a molecule.
What is a compound (molecule)?
These are also the atomic number of an atom.
What are protons?
The two particles that do not change in an isotope.
What are protons and electrons?
If an atom loses an electron.
What is a positive charge?
99.9% of an atom is made up of this.
What is empty space?
Two or more different atoms together physically but not chemically.
What is a mixture?
These make up the nucleus, and atomic mass of the atom.
What are protons and neutrons?
The word used to determine how old something is when using radioactive carbon dating.
What is a half-life?
The name for the vertical row of atoms on the periodic table.
What is a group?
The only group of fully stable elements (have full valence shells).
What are the noble gases?
The elements that make up a water molecule.
What are hydrogen and oxygen?
The number of these determines what element it is.
What are protons?
What is a parent isotope?
The total number of electrons needed in the outer/valence shell to have a stable atom.
What is 8? or What is the octet rule?