The Atom

What do you know?Part of Atom Location Mass charge

• How many of each “part” are in these atoms?

Fluorine (F) atomic number = 9 & atomic mass = 19

Copper (Cu) atomic number = 29 & mass = 64

Copy this table Part of atom Location Mass Charge

Proton Nucleus 1 Amu +1

Neutron Nucleus 1 Amu 0 (neutral)

Electron Electron “Cloud” 0 Amu -1

Amu = “Atomic Mass Unit” (not grams)

• How many of each “part” are in these atoms?

Fluorine (F) atomic number = 9 & atomic mass = 19

Copper (Cu) atomic number = 29 & mass = 64

Structure of the Atom

• Atomic number = number of protons in the nucleus AND number of electrons outside it

• Atomic mass = total mass of the protons + the neutrons. It is always a whole number.

• The number of neutrons = atomic mass – the number of protons.

Answers

• Fluorine atomic mass = 19 and atomic number is 9

• Has 9 protons (+) and 9 electrons (-)• Has 19 - 9 = 10 neutrons• Copper atomic mass = 64 and number = 29• Has 29 protons (+) and 29 electrons (-)• Has 64 – 29 = 35 neutrons

Mass of electron

• How can anything have no mass – So small compared to the rest of the atom it does

not count • For example – if I pluck one hair out of my

head – my mass on my bathroom scale will not change. The hair has mass, but it is so insignificant compared to the rest of me, we call it 0.

Atom locations

Nucleus (+) __

Electron Cloud (-)

Empty space

Nucleus

• Nucleus is (+)

++

+

--

-

-Neutron

Proton

Electron shells

• Electrons are outside the nucleus in an “electron cloud” made of energy levels

Number

Element

Symbol

Atomic Mass Atomic Number Protons

Neutrons

Electrons

1

C

2

Oxygen

3

7

4

26.98

5

P

6

Magnesium

7

Mn

8

35.45

9

11

10

30 11

126.9

12

Fe

13

Sulfur

14

20

15

19

Number

Element

Symbol

Atomic Mass Atomic Number

Protons

Neutrons

Electrons

1.

Sodium

Na

2.

Potassium

19

3.

26.98

4.

P

Isotope Notation

• Isotope Notation shows the symbol of the element with the atomic mass and atomic number on the left, atomic mass above.

• Atomic Mass 25 Symbol Mg

• Atomic Number 12

Atomic Structure using Isotope Notation

• Atomic Mass 25 Symbol Mg

• Atomic Number 12

• Number of protons = Atomic Number = 12• Number of electrons = number of protons (12)• Number of neutrons = Atomic Mass – Atomic

Number = 25 – 12 = 13

Practice

35 37

Cl Cl 17 17

• Protons = 17 17• Electrons = 17 17• Neutrons = 18 20