1. Matter Quiz Atomic Theory Notes

2. Common Core connection
Objectives
Today I will be able to:
Demonstrate knowledge of matter and energy by taking a quiz
Identify the parts of the atom and their isotopes
Informal Assessment – monitoring student interactions and questions as they complete the practice and quiz
Formal assessment – analyzing student responses to the quiz and the practice
Common Core connection
Build Strong Content Knowledge
Reason abstractly and quantitatively

3. Lesson Sequence Evaluate: Warm – Up Evaluate: Matter Quiz
Explain: Atomic Theory Notes
Elaborate: Atomic Theory Practice
Evaluate: Exit Ticket

4. Warm - Up What are some pieces of evidence for a chemical change?
What is the difference between a physical change and a chemical change?
What is the difference between homogeneous and heterogeneous mixtures?

5. Objective Today I will be able to:
Demonstrate knowledge of matter and energy by taking a quiz
Identify the parts of the atom and their isotopes

6. Homework
Finish Practice Worksheet

7. Agenda Warm – Up Matter Quiz Atomic Theory Notes
Atomic Theory Practice
Exit Ticket

8. What information can we get from the periodic table?

9. Atomic Number number of protons in the nucleus
You cannot change the number of protons!!!
Determines the identity of an element
Also the number of electrons in a neutral atom

10. Atomic Number What is the atomic number of carbon?6
How many protons and electrons would there be in a neutral atom of carbon?
6 protons and 6 neutrons
How many protons and neutrons would there be in a neutral atom of oxygen?
8 protons and 8 neutrons

11. Atomic Mass Measured in atomic mass units
The number or protons and neutrons in an atom

12. How did we arrive at measuring atomic mass in atomic mass units?
Based on the Carbon-12 scale
By international agreement, a carbon atom contains 6 protons and 6 neutrons, or 12 amu
Therefore, 1 amu is 1/12 of a carbon atom
Since the mass in grams of protons and neutrons are about the same, they both have an atomic mass unit of 1

13. Why aren’t electrons accounted for in the calculation of the atomic mass?
Electrons are small!
It takes almost 2,000 electrons to equal the mass of one proton or neutron
Electrons are assumed to have a mass of 0 amu

14. If each proton and neutron has a mass of one amu, then why aren’t the atomic masses on the periodic table whole numbers?
Isotopes of elements
atoms with the same number of protons but different numbers of neutrons

16. Ions When an atom gains or loses an electron, an Ion is formed
Cation – atom loses an electron and makes a positive ion
Example: Lithium (Li) loses one electron
It becomes Li+
Anion – atom gains an e- and makes a negative ion
Example: Sulfer (S) gains two electrons
It becomes S-2

17. Ions Examples What is the chemical symbol for the ion with:
13 protons and 10 electrons
- Al+3
7 protons and 10 electrons
- N-3

18. How many protons and electrons are present in a(n):
S-2 ion
- 16 p+ and 18 e-
Li+1 ion
- 3 p+ and 2 e-

19. Be careful with terminology!
Atomic Mass – average mass of the naturally occurring isotopes of an element
Seen on the periodic table
Mass Number – number of protons and neutrons in an atom’s nucleus
Seen in symbolic representations

20. Symbolic Representations of Elements
An atom with 7 protons and 7 neutrons has a mass number of 14 and is usually written as… N 14 7

21. Al+3 Se-2 Exit Ticket How many protons, neutrons, and electrons?27
Al+3 13
13 p+, 14 n, and 10 e- 79
Se-2 34
34 p+, 45 n, and 36 e-