Atoms and molucules Flashcards
What is an Atom?
The smallest unit of an element that behaves as the element.
What is a molecule?
A fixed number of atoms chemically joined together.
What is the relative atomic charge and mass of protons?
+1 charge, and a mass of 1
What is the relative mass of neutrons?
1
What is the mass and charge of electron?
-1 and n/a
What’s the definition of the atomic number and the proton number?
Number of protons in the nucleus of at the atom.
What is the mass number?
Sum of the number of protons and number of neutrons in nucleus of the atom.
What is an isotopes?
Atoms of the same element (i.e same atomic number, same number of protons) but different mass numbers (different numbers of neutrons)
What is the relative atomic mass?
The average mass of an atom of the element compound to the 1/12th the mass of an atom of carbon - 12.
What is an element?
Substances made up of one type of atom.
How are the chemical properties of an element determined?
By the number of electrons in the outer shell.
What do elements in the same group have?
They have the same number of outer shell electrons but different numbers of electron shells.
Why are noble gases un reactive?
They have a full outer shells of electrons
