Flashcards in 4.2 The Atom Deck (11):

1

## proton

### a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.

2

## atomic mass unit

### a unit of mass used to express atomic and molecular weights

3

## neutron

### a subatomic particle of about the same mass as a proton but without an electric charge

4

## atomic number

### the number of protons in a nucleus

5

## isotope

### an atom that has the same number of protons

6

## mass number

### the sums of the numbers of protons and neotrons

7

## atomic mass

### the mass of an atom expressed in atomic mass units

8

## gravitational force

### is the force that attracts any object with mass.

9

## electromagnetic force

### when opposite attract each other

10

## strong force

### when protons push away from each other.

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