Periodic Table Trends (Honors)

What are valence electrons?

• The total number of electrons in an atom

• The number of electrons in the outermost shell

• The number of electrons on the inner energy levels

• The number of protons in the outermost shell

The valence electrons are located on 

• the orbital closest to the nucleus
• the orbital furthest from the nucleus
• the orbital with the most electrons
• the orbital with the least electrons

Tags

NGSS.HS-PS1-1

How many valence electrons does carbon have?

• 4

• 5

• 6

• 7

Tags

NGSS.HS-PS1-1

What creates a SHIELDING EFFECT by interfering with the attractive forces between the protons and the electrons.

• nucleus

• valence electrons

• core electrons

• protons

As you move down a group, shielding

• increases because there are more energy levels and core electrons

• increases because there are more protons

• decreases because the atomic radius increases

• stays constant because the number of valence electrons stays the same

As you move across a period (row), the shielding effect

• increases

• decreases

• stays constant

• alternates for metals an nonmetals

Which element has the least amount of shielding?

• Potassium (K)

• Iron (Fe)

• Oxygen (O)

• Barium (Ba)

Which of the following elements has the largest shielding effect?

• Li

• Na

• K

• Rb

Put the following elements in order of increased shielding effect.

• Sodium (Na), Silicon (Si), Chlorine (Cl)

• Silicon (Si), Chlorine (Cl), Sodium (Na),

• Chlorine (Cl), Sodium (Na), Silicon (Si)

• Each of these has the same amount of shielding.

When shielding increases, it causes

• the atomic radius to increase

• the ionization energy to increase

• the metallic properties to decrease

• the ionic radius to decrease