Journal Entry • Describe what you know about how electrons are arranged inside atoms. • Keep writing until I ask you to stop.
Atomic Structure Drawing Atomic Models
Step 1 • Re-number the groups (columns) from 1 to 8, ignoring transition metals.
83 p+ Step 2 • Find the number of protons (from the atomic number) • Bismuth: 83 • Draw those into the nucleus.
83 p+ 126 n Step 3 • Round the average atomic mass to the nearest whole number and use that as the mass number. • A= 209 • Subtract the atomic number from it to get the number of neutrons. • #n = 126 • Draw those into the nucleus.
83 p+ 126 n energy levels: 1st 2nd 3rd 4th 5th 6th Step 4 • Look at the period number of the row that the element is in. It tells you how many energy levels there are. • Period # = 6 • Draw that number of rings around the nucleus.
83 p+ 126 n 5e- energy levels: 1st 2nd 3rd 4th 5th 6th Step 5 • Look at the new group number to tell how many electrons are in the outermost energy level. • Group # = 5 • Fill in the number of electrons in that outer level.
2e- 8e- 18e- 5e- 83 p+ 126 n energy levels: 1st 2nd 3rd 4th 5th 6th Step 6 • Starting in the 1st energy level, fill in the maximum number of electrons in the 1st, 2nd, and 3rd until you reach the outermost. • 1st = 2e- 2nd = 8e- 3rd = 18e-
Step 7 • Find the number of electrons needed to finish the diagram and add those into the 4th-6th energy levels using 8, 18 and 32 electrons only. • Find the combination that adds electrons to all levels left and still adds up to the correct number total. • The inner level(s) should always have more than the outer.
2e- 8e- 18e- 32e- 18e- 5e- 83 p+ 126 n energy levels: 1st 2nd 3rd 4th 5th 6th Step 7 • already added to diagram (2 + 8 + 18) + 5 = 33e- • Need to add to diagram 83 – 33 = 50 e- in 4th and 5th • 18 + 32 = 50 • 32 must be in 4th and 18 must be in 5th.