1. Q2 Name 3 subatomic particles. What particle has no charge?
Which atom has the least mass?
What is true about all neutral atoms?
How can the atomic number of an atom be determined?

2. Today’s Objective:
I understand the development of current atomic theory.

5. Same protons but different neutrons
Isotope
Same protons but different neutrons
Same atomic number
Difference of # of neutrons
Isotope # is # of p + n

6. What would it take for an atom to have an overall neutral charge?
Same # of protons as electrons

7. Atomic Number
The number of protons in the nucleus
All atoms of different elements have a different number of protons

8. The number of protons + neutrons
Atomic Mass Number
The number of protons + neutrons
Neutrons = Mass # - Atomic #
Mass # can change and the element stays the same

10. Metal that forms bright blue solid compounds
Chemical Symbols
ONE capital letter followed by lowercase letter(s) if necessary.
Often not the first letter of its name
Co vs. CO
Metal that forms bright blue solid compounds
Poisonous gas

11. How could the mass contain a decimal if it is the number
of protons + neutrons?

12. Isotope
Mass
Abundance
Li-6 6
7.5%
Li-7 7
92.5%

13. The weighted AVERAGE of the masses of all isotopes as found in nature
Atomic Mass:
The weighted AVERAGE of the masses of all isotopes as found in nature
Li-7
Li-6

14. AMU: Atomic Mass Unit
How much 1/12 of a
Carbon -12 weighs

15. Calculating Atomic Mass Number:

16. Boron has 2 common isotopes: B-10 & B-11
In nature, 80% of all Boron is B-11 and 20% is B-10
Mass x abundance
B-10: 5P + 5N = 10amu
X .20
= 2
B-11: 5P + 6N = 11amu
X .80
= 8.8
Add: = 10.8

17. Whiteboard Practice

18. What is the charge of this atom?
Negative -1

19. Positive
+ 1
What is the charge of this atom?

20. The atomic mass of an atom is 28. It’s atomic number is 10
The atomic mass of an atom is 28. It’s atomic number is 10. How many neutrons does it have?
18 neutrons
28-10 = 18

21. What is the difference between Carbon-6 and carbon-7?
# of Neutrons

22. A neutral atom has 15 electrons. How many protons does it have?

23. A neutral atom has 94 electrons. How many protons does it have?

24. All atoms of an element
have the same
A. Mass number
B. Number of isotopes
C. Atomic number
D. Number of neutrons

25. What is the charge of this atom?
Neutral

26. A neutral atom has 65 electrons. How many protons does it have?