C02.6 Periodic Trends 1 Lecture

Multiple Choice

Atoms are mostly...

• solids

• protons

• full of subatomic particles

• electron cloud (empty space)

Multiple Select

Which of these are true about Coulomb's Law? Pick 2.

• larger charges = stronger force

• smaller charges = stronger force

• greater separation = weaker force

• greater separation = stronger force

Multiple Choice

What is the atomic radius of the iodine atoms shown in the picture?

• 266 pm

• 133 pm

• 266 Å

• 133 Å

Multiple Choice

What is circled in this radius vs atomic number graph?

• periods

• groups

​Answer the Atomic Radii and the Size of Atoms Eamples by looking up the elements in the examples on your periodic table and applying the periodic trend.

Multiple Choice

According to periodic trends, which atom is larger?

• Carbon

• Nitrogen

Multiple Choice

According to periodic trends, which atom is larger?

• Germanium

• Silicon

• can't tell from using just the periodic trend

Multiple Choice

According to periodic trends, which atom is larger?

• Magnesium

• Barium

• can't tell from using just the periodic trend

Multiple Choice

According to periodic trends, which atom is larger?

• Aluminum

• Germanium

• can't tell from using just the periodic trend

Reorder

Based on the periodic trend for atomic radius.

Put the following elements in order of increasing size. (smallest on the left, largest on the right)

• Ca

• Sr

• Rb

• Cs

1

2

3

4

• 1
• 2
• 3
• 4

Multiple Choice

Why do atoms in the same group get bigger as you go down the group?

• each step down adds another electron shell

• a decrease in Z_eff causes the electron cloud to spread out

• an increase in shielding electrons increases the force of attraction

Fill in the Blanks

What is the effective nuclear charge of this atom?

​Answer the Predicting Ion Size Examples using the periodic trends.

Reorder

Using the periodic trend.

Reorder the ions in order of increasing size (L to R)

Smallest on the left, largest on the right

• O^2-

• S^2-

• P^3-

• As^3-

1

2

3

4

• 1
• 2
• 3
• 4

Multiple Choice

Which one is larger?

• Br

• Br ^–

Multiple Choice

Which one is larger?

• Na

• Na⁺

Activate Self Pace Mode

Use your notes to answer the following questions.

Multiple Choice

As you move down the periodic table atoms get bigger.  This is because ____________.

• The atoms have more mass.
• The atoms have more protons.
• The atoms have more energy levels
• The atoms have more nuetrons

Multiple Choice

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

• the atoms have more mass, which increases the gravitational pull

• it doesn't, atoms get bigger going from left to right because of the additional protons and electrons that are being added.

• effective nuclear charge tends to increase

• atoms lose energy levels make them smaller

Multiple Choice

The atom with the largest atomic radius in Group 18 is - 

• Ar
• He
• Kr
• Rn

Multiple Choice

According to the periodic trend, which periodic group has the smallest atomic radius?

• Alkali metals

• Halogens

• Noble Gases

• Transition metals

Multiple Choice

If the distance between the two nuclei is 100pm, what is the atomic radius?

• 200 pm

• 100 pm

• 50 pm

• 25 pm

Multiple Choice

When looking at elements in the same period, why does increasing the effective nuclear charge make the atoms smaller?

• It increases the force of attraction between the protons thus pulling the protons closer together and making the atom smaller

• It increases the force of attraction on the valence electrons thus pulling the electrons closer to the nucleus and making the atom smaller

• If reduces the number of main energy levels or shells thus making the atom smaller

• It increases the force of repulsion the electrons have on each other thus causing the electrons to spread out and making the atom smaller

Multiple Choice

Which of the following is the smallest?

• Na⁺

• Mg²⁺

• Al³⁺

Multiple Choice

Which of the following is smaller?

• Sr²⁺

• Sr

​The End

​You can exit the lecture.