Periodic table and electron configuration

Which of these atoms ends its configuration in s2?

• Fe

• Ne

• Be

• S

How many valence electrons (those in the last layer) has an atom with an electron configuration of "1s2 2s2 2p1"?

• 5

• 3

• 1

• 2

What kind of element is an atom whose electron configuration ends in "d3"?

• noble gas

• nonmetal

• metal

• transition metal

How many energy levels has an atom with the electron configuration "1s2 2s2 2p6 3s2 3p6 4s2 3d1"?

• 1

• 2

• 3

• 4

What electron configuration corresponds to the atom with the LARGEST RADIUS?

• 1s2 2s2 2p6 3s1

• 1s2 2s2 2p6

• 1s2 2s2 2p2

• 1s2 2s2

What atom of the 15th Group has the LARGEST RADIUS?

• N

• P

• As

• Sb

What atom of the 3rd Period has the LARGEST RADIUS?

• Na

• Mg

• Al

• Si

Beryllium is larger than Boron, because...

• ... it has more electron layers

• ... it has fewer electron layers

• ... its protons attract the electrons more weakly

• ... its protons attract the electrons more strongly

What configuration do most atoms tend to achieve?

• The one that makes them electrically neutral (same number of protons as of electrons)

• The one of the closest noble gas (typically, **s2 **p6)

• One that makes them positive ions (cations)

• One that makes them negative ions (anions)

What is the main characteristic of METALLIC ATOMS?

• ... they tend to give electrons away

• ... they tend to attract new electrons

• ... they are very stable and rarely react

• ... they are all extremely reactive