Warm Up

• Write the electron configuration for F.• Then draw the orbital diagram.

Bohr’s Model• Shows the total

number of electrons in each energy level (shell).

• Notice the electrons are paired, just as they are in the orbital diagram.

bohr_atom.gif

Relation between shell and subshell• First shell:– 1s

• Second shell:– 2s and 2p

• Third shell:– 3s, 3p and 3d

• Fourth shell:– 4s, 4p, 4d and 4f

• Predict – 8th shell…– 8 subshells!

The number of subshells in equal to the shell (period) number!

Total electrons in each shell• First shell:– 1s has 2

• Second shell:– 2s has 2 and 2p has 6 = 8

• Third shell:– 3s has 2, 3p has 6, 3d has 10 = 18

• Fourth shell:– 4s has 2, 4p has 6, 4d has 10, 4f has 14 = 32

Draw Bohr’s model for…

• H Predict the change for Li

Why is the electron green?

Because it is in an s orbital! (outlined in green)

Draw Bohr’s model for…

• H• Li 1s22s1

Predict the change for Na

Draw Bohr’s model for…

• H• Li• Na

1s22s22p63s1

Predict the change for K

We are taking our orbital diagram and cutting apart the separate shells and then bending them into a circle!

Draw Bohr’s model for…

• H• Li• Na• K

What change did you notice in the size of the atom?

1s22s22p63s23p64s1

Size increased as more energy levels (shells) were added!

Draw Bohr’s Model for…• Li• Be• B• C• N• O• F• Ne

What occurred at the particle level across this period?

Predict the change that will occur as we go across the second period.

Added an additional electron AND an additional proton.

Atomic Radius Trend• Across a period, the atomic radius

decreases due to the increased effective nuclear charge.– There are more protons in the nucleus

to attract and pull in the electronsbgrn1626l.jpg

650px AtomicRadius.png‑

650px AtomicRadius.png‑

• Down a family, the atomic radius increases, due to the additional energy levels (shells)

Research• Groups of 1 to 4• Research either– Electronegativity– Electron affinity– Ionization energy

• Make a claim – How does the term relate to atomic radius trend

• Give your evidence– Insert pictures of your findings

• Explain your reasoning– This is where your VOICE comes into play

Make a video of your claim, evidence and reasoning using

educreations.