The Atom and Electron Configuration

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What is an atom?

The smallest particle of an element that has certain properties of that element

What are the three subatomic particles that make up an atom?

Protons, neutrons, and electrons

What does subatomic mean?

Smaller than an atom

What is the symbol for protons?

P

What is the symbol for electrons?

e-

What is the symbol for neutrons?

n

What charge do protons have?

+1

What charge do electrons have?

-1

What charge do neutrons have?

They have no charge

If +ve and -ve charges attract each other, what subatomic particle attracts what other subatomic particle?

Protons attract electrons

If all atoms have an equal number of p and e-, are atoms positive, negative, or neutral?

Neutral

What is the relative mass of a proton?

1 amu

What does amu stand for?

Atomic mass unit

What is the relative mass of a neutron?

1 amu

What is the relative mass of an electron?

1/1700 amu (basically 0)

Where do you find protons?

In the nucleus

Where do you find electrons?

In energy shells

Where do you find neutrons?

In the nucleus

What is the nucleus?

The centre of an atom that contains protons and neutrons

What do electrons occupy?

Distinct energy shells around the nucleus

What subatomic particles takes up 99.99% of an atoms volume?

Electrons

What is matter?

Anything with mass and volume

Where does the mass of an atom come from?

Protons and neutrons in the nucleus

Where does the volume of an atom come from?

Electrons in energy shells that surround the nucleus

How do you read the periodic table?

What is the atomic number of an element?

The number of protons in an atom

How do you know how many electrons an atom has?

Atoms are neutral and always have the same number of electrons as they do protons

What is the atomic mass?

The average mass of the atoms in an element

Why is the atomic mass sometimes a decimal?

Because of isotopes

What is an isotope?

A variant of an element which differs in the number of neutrons in the atom.

Do isotopes differ in how many protons there are in the atom?

No, all atoms of an element will have the same amount of protons

How do you calculate now many neutrons are in an atom?

Atomic mass minus the atomic number = the number of neutrons

What do you do if you calculate the number of neutrons in an atom and you get a decimal number?

You round, the number of neutrons is always a whole number

How do you write the symbol of an element?

The first letter is always capital and the rest are lowercase (See picture for example)

If Carbon has 6 protons, how many electrons does it have?

6

If carbon has an atomic mass of 12 and an atomic number of 6, how many neutrons does it have?

6

What order do you fill the shells when drawing bohr diagrams?

You always fill the innermost shell, then fill each shell after that

What shell has the lowest energy level?

The first shell

How many electrons can be on the first shell?

2

How many electrons can be on the second shell?

8

How many electrons can be on the third shell?

8

What is the electronic configuration of an atom?

The number of electrons in each shell

How do you write the electronic configuration

You write now many electrons are in the first shell, then the second shell, then the third. Ex. A chlorine atom has 17 electrons. First you fill the first shell, which holds two electrons. Then you fill the second shell, which holds 8 electrons. Then you fill the third shell, and you put 7 electrons in that shell. The electronic configuration for a chlorine atom would be 2, 8, 7. The first shell holds 2 electrons, second 8, and third 7.