bellwork9.12.2011 1.draw a picture of an atom. label the nucleus, protons, neutrons, and electrons....

Bellwork9.12.2011

1.Draw a picture of an atom. Label the nucleus, protons, neutrons, and electrons.

2.Give the charges of each of the 3 subatomic particles.

3.Using the periodic table (or your knowledge), list 2 elements and describe their use to us!

Subatomic Particles

Particle Symbol Charge RelativeMass

Electron e- 1- 0

Proton p+ + 1

Neutron n 0 1

Atomic Number

Counts the number of

protons in an atom

Atomic Number on the Periodic Table

11

Na

Atomic Number

Symbol

All atoms of an element have the same number of protons

11

Na

11 protons

Sodium

Learning Check

State the number of protons for atoms of each of the following:

A. Nitrogen (N)

1) 5 protons 2) 7 protons 3) 14 protons

B. Sulfur (S)

1) 32 protons 2) 16 protons 3) 6 protons

C. Barium (Ba)

1) 137 protons 2) 81 protons 3) 56 protons

Mass Number

Counts the number of

protons AND neutrons

in an atom

We can find this, and the atomic number, in something called. . .

Atomic Symbol

Shows the mass number and atomic

number

Na

How to find the # of Neutrons

• The difference between the mass number and the atomic number.

mass number – atomic number = # of Neutrons

How to find the # of Electrons

An atom is neutral So the net charge is zero

Number of protons = Number of electrons

Atomic number = Number of electrons!

Subatomic Particles in Some Atoms

16 31 65 O P Zn

8 15 30

e-

p+

n

Isotopes

Atoms with the same number of

protons, but different numbers of

neutrons. In other words. . . atoms of the same element

(same atomic number) with different mass

numbers

Isotopes of Carbon

Isotopes of Helium

Learning Check

Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C.

12C 13C 14C 6 6 6

#p _______ _______ _______

#n _______ _______ _______

#e _______ _______ _______

Learning Check

An atom of zinc (Zn) has a mass number of 65.

A. Number of protons in the zinc atom

1) 30 2) 35 3) 65

B. Number of neutrons in the zinc atom

1) 30 2) 35 3) 65

C. What is the mass number of a zinc isotope

with 37 neutrons?

1) 37 2) 65 3) 67

Learning Check

Write the atomic symbols for atoms with the following:

A. 8 p+, 8 n, 8 e- ___________

B. 17p+, 20n, 17e- ___________

Atomic Mass on the Periodic Table

11

Na

22.99

Atomic Number

Symbol

Atomic Mass

Atomic Mass

Atomic mass is the weighted average mass of all the isotopes of that atom.

11

Na

22.99

Example of an Average Atomic Mass

Cl-35 is about 75.5 % and Cl-37 about 24.5% of natural chlorine.

Bell Work 9/13/2011

1. What is the atomic number?

2. What is the mass number?

3. Complete the following and give there element names:

14C 44Ca 80Se 6 20 34

#p _______ _______ _______

#n _______ _______ _______

#e _______ _______ _______

The Periodic Table

• An arrangement of elements in which the elements are separated into groups based on properties.

Atomic Number

• The elements are listed by increasing atomic number

ATOMIC # Increases

• Each horizontal row, there are seven

Period

• Each vertical column• Elements that share the same group

have similar chemical and physical properties.

Group

If you didn’t finish these during class do the following for homework:

• p. 111 #15 and 16

• p. 112 #17 and 18

• p. 113 #19 and 20

• p. 116 #21 and 22

• p. 117 #23 and 24

Homework (maybe?)