Periodicity I

Across a period from left to right , atomic radius

• decreases

• increases

• increases, then decreases

• decreases, then increases

What makes a valence electron more attracted to the nucleus?

• less distance between the nucleus and having less protons
• less distance between the nucleus and having more protons
• more distance between the nucleus and having less protons
• more distance between the nucleus and having more protons

Tags

NGSS.HS-PS1-3

Atomic radius generally increases as we move __________.

• down a group and from right to left across a period

• up a group and from left to right across a period

• down a group and from left to right across a period

• up a group and from right to left across a period

Which of the following elements has the smallest atomic radius?

• Sulfur

• Chlorine

• Aluminum

• Sodium

Tags

NGSS.HS-PS1-1

As you move across the periodic table atoms tend to get smaller because, ______________.

• the atoms have more mass.
• the atoms have less mass
• the atoms have more protons.
• the atoms have less electrons.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which is smaller... Mg or Mg²⁺ ?

• Mg because it gains an energy level
• Mg due to extra electron repulsion
• Mg²⁺ because of extra electron repulsion
• Mg²⁺ because it loses an energy level

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Why doesn't having more protons increase the attraction down a column?

• there are more valence electrons in the outermost energy level

• actually, there aren't more protons in the nucleus down the column

• as energy levels are added, non-valence electrons block the extra protons from attracting ve-

• more neutrons block the extra protons

List the following from largest to smallest atomic radius.
P, Cs, Co, Sr

• P, Co, Sr, Cs
• P, Cs, Co, Sr
• Cs, Sr, Co, P
• Sr, Cs, Co, P

Tags

NGSS.HS-PS1-1

When Z_eff increases, the nucleus attraction

towards electrons become

• Weaker

• Stronger

• Remain the same

What happens to atomic radius across a period?

• the atoms get bigger because the nucleus is bigger as more protons are added

• the atoms get bigger because there are more ve-

• the atoms get smaller because with more attraction to the extra protons, the e- cloud moves closer to the nucleus

Tags

NGSS.HS-PS1-1