1. An atom is the smallest particle of an element that retains the chemical identity of the element. Three Parts of Atom Particle ChargeMassAtomic mass units Proton+1 1.67x 10 -24 g 1 amu Neutron 0 1.67x 10 -24 g 1 amu Electron -1 9.11x 10 -28 g 0 amu

2. Where are they? Nucleus is made up of protons and neutrons. Electrons move around the nucleus. Mass is concentrated in the nucleus. 99.97% of the mass is in the nucleus.

3. How big are atoms? If nucleus is size of a golf ball, the electrons are how far away? 1 mile! Lots of empty space How big are they? 6.02 x 10 23 atoms in 12 grams of carbon.

4. How many protons? The atomic number is the number of protons in the nucleus of the atom. Look at the periodic table for this. The number of protons identifies the element.

5. How many neutrons? The number of neutrons may vary. An isotope is an atom that has the same number of protons as other atoms of the same element, but different number of neutrons. Same atomic number = same element Protons + Neutrons = Atomic Mass Isotopes have different atomic masses, because they have different number of neutrons.

6. HOW MUCH FOR A ROOT BEER? A NEUTRON WALKED INTO A BAR AND ASKED…

7. FOR YOU, BUDDY… NO CHARGE! THE BARTENDER SAID

8. How many electrons? The number of electrons equals the number of protons in a neutral atom An ion is a charged atom in which the number of electrons can increase or decrease. More electrons than protons, charge is negative Fewer electrons than protons, charge is positive

9. CARBON Carbon has 6 protons6 amu 6 neutrons6 amu 6 electrons0 amu Total atomic mass = 12 amu

10. How do we write this? Carbon-12 C-12 12 C 12 6 C 0 The periodic table tells us that carbon has 6 protons. The mass is 12 amu and equals protons plus neutrons, so it has 6 neutrons. It is neutral (has no charge), so it has 6 electrons.

11. Isotope of carbon Carbon-14 C-14 14 C 14 6 C 0 The periodic table tells us that carbon has 6 protons. The mass is 14 amu and equals protons plus neutrons, so it has 8 neutrons. It is neutral (has no charge), so it has 6 electrons.

12. What’s the safe answer here? ??? Carbon-14 isotope said to Carbon-12 isotope, “Does these neutrons make my mass look big ?

13. Ion of carbon Carbon-12 C-12 12 C 12 6 C +4 The periodic table tells us that carbon has 6 protons. The mass is 12 amu and equals protons plus neutrons, so it has 6 neutrons. It is positive (it lost 4 electrons), so it has only 2 electrons.

14. Are you POSITIVE? OH NO!!! I think LOST an ELECTRON!!

15. A n (- or +) E Z E = element symbol Z = atomic number = # protons (identifies element) A = atomic mass = # protons + # neutrons n = charge (+ if fewer electrons than protons) (- if more electrons than protons)

16. What is the name of the element that has… 5 protons 17 protons 25 protons 82 protons 92 protons

17. What is the chemical symbol of… The atom with 8 protons 11 protons 9 protons

18. How many protons and electrons in atoms of…? vanadium? nitrogen? argon? potassium?

19. What is the chemical symbol of… The ion with 8 protons and 10 electrons 11 protons and 10 electrons 9 protons and 10 electrons

20. Write the chemical symbol for the ion with… 12 protons and 10 electrons 74 protons and 68 electrons 95 protons and 89 electrons

21. Write the chemical symbol for the ion with… 33 protons and 36 electrons 29 protons and 27 electrons

22. Write the chemical symbol for the atom with… 5 protons and 6 neutrons 13 protons and 14 neutrons 8 protons and 8 neutrons

23. Show 3 ways to write The atom with 53 protons and atomic mass 131 How many neutrons are in this isotope?

24. How many protons, neutrons, electrons… 59 2+ Ni 28

25. How many protons, neutrons, electrons… 91 4+ Zr 40

26. How many protons, neutrons, electrons… 140 3+ Ce 58

27. How many protons, neutrons, electrons… 79 2- Se 34

28. How many protons, neutrons, electrons… 45 3+ Sc 21

29. How many protons, neutrons, electrons… 13 4- C 6

30. Write the complete chemical symbol for the ion with… 84 p 125 n 80 e

31. Write the complete chemical symbol for the ion with… 27 p 32 n 25 e

32. Write the complete chemical symbol for the ion with… 73 p 108 n 68 e

33. Write the complete chemical symbol for the ion with… 31 p 39 n 28 e