1. Foldables: Atoms
Terms

2. The basic unit of matter
Atom
The basic unit of matter
It consists of a nucleus (with protons and neutrons) and electrons

3. Positively charged particles Found in the nucleus Mass: 1.0073 amu
Protons
Positively charged particles
Found in the nucleus
Mass: amu
(amu= atomic mass unit; 1amu= x 10^-24 g)

4. Particles found in the nucleus No electrical charge Mass: 1.0087 amu
Neutrons
Particles found in the nucleus
No electrical charge
Mass: amu

5. Negatively charged particles Mass: 5.4858 x 10^-4 amu
Electrons
Negatively charged particles
Mass: x 10^-4 amu
Found in a cloud outside the nucleus

6. The number of protons in the nucleus of an atom
Atomic number
The number of protons in the nucleus of an atom
In a neutral atom, the number of protons is equal to the number of electrons

7. Sum of the number of protons and neutrons
Mass number
Sum of the number of protons and neutrons
Mass number = protons + neutrons

8. Isotope
Atoms of the same element that have the same number of protons but different number of neutrons

9. Atomic weight
The average of the masses of all the naturally occurring isotopes of an element

10. A positively, or negatively, charged atom
Ion
A positively, or negatively, charged atom
Atoms become ions because they gain or lose electrons