 # ATOMS.

## Presentation on theme: "ATOMS."— Presentation transcript:

ATOMS

Atom Smallest part of any element that contains all properties of that element.

The center of an atom. It contains two particles: neutron and proton
The center of an atom. It contains two particles: neutron and proton. Has a positive charge. Nucleus

3 main subatomic particles are the proton, neutron and electron.
THESE particles are SMALLER than an atom. ***LOOK at the difference in size!!! WOW…an electron is SO SMALL!!!

Positively charged particle found in the nucleus.
Proton

Neutron Particle in the nucleus of an atom that does not have a charge. It is a neutral particle.

Particle orbiting the nucleus of an atom. It has a negative charge.
Electron

Valence Electrons – the electrons in the outermost energy level/shell of an atom; they determine how an element will react with other substances.

represents the number of protons found in the atom’s nucleus.

Protons + Neutrons=Mass Number
The sum of the number of protons and neutrons found in the nucleus of the atom for that element. Protons + Neutrons=Mass Number

Atomic Number 6 C Carbon 12.011 Symbol Element Name Atomic Mass

This is what gives the atom a neutral charge.
Number of Protons Equals Number of electrons This is what gives the atom a neutral charge.

The average mass of one atom of an element.
ATOMIC MASS The average mass of one atom of an element.

(atomic mass unit)- the SI unit for the masses of particles in an atom.

The Big Picture!

Neutron Proton Electron

How many neutrons does an atom contain if its atomic mass is 65 and it contains 30 protons?

Protons + Neutrons ? =

Protons + Neutrons Mass Number =

What is the smallest part of any element that contains all properties of that element?
Atom

What are the particles that are smaller than an atom called?
Subatomic Particles

What are the 3 main subatomic particles that make up an atom?
Proton Neutron Electron

What is the center of an atom called?
Nucleus

What are the two particles found in the nucleus of an atom?
Proton and Neutron

What type of charge does the nucleus of an atom have?
Positive

What is the positively charged particle found in the nucleus?
Proton

The subatomic particle that is neutral is the
Neutron

What is the negative charged particle that orbits the nucleus of an atom?
Electron

Why does the atom have a neutral charge?
The number of protons in the nucleus of an atom equals the number of electrons orbiting the nucleus.

How do we determine the number of electrons in an atom?
Number of electrons equals the number of protons.

17 The element chlorine has an atomic number of 17, it has
_____ protons in its nucleus. 17

Mass Number Practice

How many protons does an atom have if its atomic mass is 12 and it has 6 neutrons?

What is the mass number if an atom has 2 protons and 2 neutrons?

Which element has an mass number of 12 and contains 6 neutrons?