electron config

if n = 3, which values of l (the angular momentum quantum number) are allowed?

0,1,2

how many orbitals are in a d sublevel?

5

Which set of quantum numbers (n, l, ml, ms) is NOT allowed?

(1,1,0,+1/2)

pauli exclusion principle: two electrons in the same orbital must have...

opposite spins

What is the electron configuration of sodium (Na)?

1s2 2s2 2p6 3s1

which sublevel fills right after 3p?

4s

What is the noble gas configuration of chlorine (Cl)?

[Ne] 3s2 3p5

Which element has the configuration [Ar] 4s2 3d6?

Iron (Fe)

how many unpaired electrons does an oxygen atom have?

2

Iron is in Period 4. Its d electrons are in which sublevel?

3d

elements in the same group have the same number of...

valence electrons

Which family includes F, Cl, Br, and I?

halogens

How many valence electrons does sulfur (S) have?

6

why are the noble gases so unreactive?

their outer energy level is full

An element's electron configuration ends in ns1. Which family is it in?

alkali metals

Going DOWN a group, atomic radius...

increases

Going ACROSS a period (left to right), atomic radius...

decrease

why do atoms get smaller from left to right across a period?

more protons pull the same energy level in tighter

Rank by atomic radius, smallest to largest: K, Br, Cs

Br < K < Cs

true or false: chlorine has more electrons than sodium, so chlorine is the larger atom.

false

first ionization energy is the energy needed to...

remove the outermost electron from a neutral atom

Going ACROSS a period (left to right), first ionization energy generally...

increases

Which element has the HIGHEST first ionization energy?

Helium (He)

Rank by first ionization energy, lowest to highest: Ca, Ba, Mg

Ba < Ca < Mg

First ionization energies: X = 419 kJ/mol, Y = 1251 kJ/mol. One is K, one is Cl. X is...

Potassium (K)

why does cesium react with water more violently than lithium?

its outer electron is farther away and easier to remove