Subatomic Particles Basics

**Why aren't electrons included here?

The mass is so small it becomes insignificant

What happens when the electrons are lost/gained?

The atom becomes a charged particle or an ion atoms: neutral.

What does amu stand for?

atomic mass unit

If amu is a relative unit, what does that mean?

A unit that's not measured directly. It's based off of another measurement

What's an isotope?

Atoms of the same element with a different # of neutrons (Therefore they'll all have different masses)

What does the bottom number indicate?

Charge

To find the number of electrons. Since all atoms must be electrically ___________, the number of electrons must be _________ to the number of protons

Neutral, Equal. Atoms: protons = electrons

Definition of mass number

Number of protons and neutrons

Which sub. particles contribute to charge?

Protons (+1) and electrons (-1)

Which subatomic particle contribute to the mass?

Protons and Neutrons both = 1 amu

What is electron notation? Where is a electron located?

0/1 e . Outside of the nucleus

What is neutron notation? Where is a neutron located?

1/0 n . In the nucleus

What is proton notation? Where is a proton located?

1/1 H or 1/1 P. In the nucleus

How many subatomic particles are there? What are they?

3! Protons, neutrons, electrons

What mass column should be used for calculating atomic mass?

Atomic mass (Amu, u)

Which subatomic particles will be gained or lost to change the charge? Why based off of location?

Electrons because they're free to move, not bound in the nucleus.

What does the top number indicate?

Mass

What is atomic mass?

The weighted average of all the NATURALLY occurring isotopes of an element

Formula for Atomic Mass

[ (mass(1) x %) + (mass(2) x %) + ...] / 100

Where is most of the mass of an atom located?

inside the nucleus

Anions?

negatively charged ions

What is amu defined as?

one twelfth the mass of a carbon-12 atom (1.67x10^-24 grams)

Cations?

positively charged ions