Boron has 5 protons, and if not combined with anything else, has 5 electrons. Boron has 6 neutrons. 11 atomic mass – 5 protons = 6 neutrons 5 B Boron

5 P+ 6 N e- 5 B Boron

Each electron shell can hold a maximum number of electrons. ShellMax 1 st 2 2 nd 8 3 rd 8 or 18 P+ N 2 e- 8 e- 2, 8, 8

Carbon has 6 electrons. 2 go in the first shell, leaving 4 for the second shell. 2, 8, 8

Sodium has 11 electrons. 2 go in the first shell, 8 go in the second shell, leaving 1 for the third shell. 2, 8, 8

How many electrons are in the outer shell of Oxygen? 8 O Oxygen P+ 8 N 2, 8, 8

These outer electrons are VALANCE ELECTRONS. Valance electrons control how an atom interacts with other atoms. 8 O Oxygen P+ 8 N

10 Ne Neon Na Sodium N Nitrogen Al Aluminum , 8, 8

On the next two pages of your notebook, copy down the Periodic Table boxes for the following four elements. Write out how many protons, electrons, and neutrons each have. Draw the elements, and highlight the valance electrons. Lithium (3) Sodium (11) Argon (18) Neon (10) 2, 8, 8

5 P+ 6 N e- 5 B Boron

DSJ 3 + sentences: Do any atoms have zero protons, neutrons, or electrons? If so, which elements. If not, why not? Element of the day: Copy the box, draw the atom (large). Identify the number of protons, neutrons, and electrons. Highlight any valance electrons. 14 Si Silicon 28.09

1 H Hydrogen 1.008

14 Si Silicon P+ 14 N

14 P+ 14 N

Dimitri Mendeleev developed the Periodic Table. In 1863 there were 56 known elements. He earned the 1906 Nobel Prize in Chemistry.

ParticleChargeLocationMassAbbrev. ProtonPositiveNucleus1P+ NeutronNoneNucleus1N ElectronNegative“Cloud”0e-

P A r t r i d G e Ar is the chemical symbol for Argon Ge is the chemical symbol for Germanium

P A r t r i d g e 1818 P + Argon22 N Ar18 e valance electrons Mass of 40 atomic units 18 P+ 22 N