# Do Now - PowerPoint PPT Presentation

1 / 29

Do Now. Draw a bohr model for Boron. Do Now. Describe what makes a source reliable and accurate?. Atomic Number, Atomic Mass, and Isotopes. Happy Pt Tuesday!!!!. By the end of the class today I will be able to…. Student will understand the symbol for an isotope.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Do Now

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

### Do Now

• Draw a bohr model for Boron

### Do Now

• Describe what makes a source reliable and accurate?

## Atomic Number, Atomic Mass, and Isotopes

Happy Pt Tuesday!!!!

### By the end of the class today I will be able to…

• Student will understand the symbol for an isotope

If we made a scale model of an atom and wanted to use Cowboy Stadium as our electron cloud, the nucleus of the atom would be the size of the eraser on the end of your pencil. An electron would still be smaller than the point on a straight pin.

### What do these boxes mean??

Number of protons/ Atomic Number

All atoms of the same element have the same number of protons

Mass Number

p+

e-

n0

### Number of Protons, Neutrons, & Electrons

# Protons =

How to Use the Periodic Table

# Electrons =

# Neutrons =

-

=

Example 1: Argon

### Isotope Symbol

X: element symbol

### Isotope Symbol

A: Mass Number

#protons + # neutrons in the nucleus

Always larger than Z

Z: Atomic number

#protons

Or Sodium-23

Na

23

11

Na

Na

23

24

11

11

### Example Problem

• Write the nuclear notation for the chemical element that has 6 protons and 8 neutrons

### #1

• Write the Nuclear notation for the chemical element that has 17 protons and 16 neutrons (in your table)

Clor Chlorine-33

33

17

### #2

How many protons are in the isotope 54Cr? (Chromium-54) (add it to your table)

24 (like every atom of Chromium)

### #3

How many neutrons are in the isotope 42Ca? Number or protons? (add it to your table)

22 neutrons

### #4

How many electrons are in the isotope 23Na? Write it’s nuclear notation (add to table)

11 electrons

### Average Mass of Subatomic Particles

Atomic Mass Unit

1 amu= 1.66 x 10-24 g

x

# e-

# p+

# n0

Mass of n0

Mass of p+

Protons

### Example

Example 7: Mass of Beryllium

x

x

+

+

+

+

=

=

Mass of e-

Neutrons

Electrons

4 Protons

4 Electrons

5 Neutrons

Sodium

Fluorine

### Gallery walk

• Walk around to the different pictures of isotopes

• Identify which isotope it is and fill out the information in your packet

• Figure out – WHAT IS THE DIFFERENCE?

Definition

Examples

Isotope

Non-Examples

Drawing or Traits

Isotopes

### Four Isotopes of helium

What sub-atomic particle(s) are the same for the isotopes of Helium?

What sub-atomic particle(s) are different for the isotopes of Helium?

Are these four isotopes neutral? Why or Why not?

### Workout!

Write the following as an isotope symbol…

4. Copper-63

5. Copper-64

6. Lithium-7

7. Lithium-6

### Example Problem

• How many neutrons are in the isotope of 26Mg?

Number of Neutrons = A-Z

### #1

How many neutrons are in the isotope 48Ti?

26 neutrons

### Example Problem

How many electrons are in the isotope 23Na? (you can assume the atom is neutral)

11 electrons