Periodic Table and Periodic Trends

As you move down a group, atomic radius increases because - 

• you add more and more neutrons

• you add more and more protons

• you add more and more shells (energy levels)

• you add more atomic mass

Answer explanation

As you move down a group, more energy levels (shells) are added, which increases the distance between the nucleus and the outermost electrons, resulting in a larger atomic radius.

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

• Ar

• He

• Kr

• Rn

Answer explanation

In Group 18, the atomic radius increases down the group due to the addition of electron shells. Radon (Rn) is the heaviest noble gas and has the largest atomic radius compared to Argon (Ar), Helium (He), and Krypton (Kr).

As you move down a group / family, valence electrons are in a higher _______ ______?

Answer explanation

As you move down a group in the periodic table, the valence electrons occupy higher energy shells, which means they are further from the nucleus and have higher energy levels.

Tags

NGSS.HS-PS1-1

As you move across the periodic table from left to right, the atomic radius decreases.  This is because - 

• the number of protons increases, so attraction to electrons increases

• the number of energy levels increases

• the number of electrons increases

• the atomic mass increases

Answer explanation

As you move across the periodic table, the number of protons increases, enhancing the positive charge in the nucleus. This increased attraction pulls electrons closer, resulting in a smaller atomic radius.

Tags

NGSS.HS-PS1-1

The atom with the largest atomic radius in Period 4 (row 4) is - 

• K

• Kr

• Fe

• Fe

Answer explanation

In Period 4, atomic radius increases down the group. Potassium (K) is in Group 1 and has the largest atomic radius due to having fewer protons and a larger electron cloud compared to Kr and Fe, which are further to the right.

Tags

NGSS.HS-PS1-1

Francium (Fr) has the lowest ionization energy in Group 1 because - 

• it has the smallest number of valence electrons

• it has the greatest atomic mass

• it has the greatest number of protons, so it attracts its electrons the strongest

• its 1 valence electron is very far from the nucleus, so little energy is needed to remove it

Answer explanation

Francium has its only valence electron far from the nucleus, resulting in a weak attraction. This means less energy is required to remove it, leading to the lowest ionization energy in Group 1.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The element with the smallest ionization energy in Period 6 is - 

• Rn

• Cs

• Os

• Tm

Answer explanation

The element with the smallest ionization energy in Period 6 is Cs (cesium). As an alkali metal, Cs has a lower ionization energy compared to other elements in the period, making it easier to remove an electron.

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.

Answer explanation

As you move across the periodic table, atoms get smaller because they have more protons. The increased positive charge in the nucleus pulls the electrons closer, reducing the atomic size.

Tags

NGSS.HS-PS1-1

The energy required to remove electrons is the definition of: 

• Electronegativity

• Atomic Number

• Atomic Radius

• Ionization

Answer explanation

The energy required to remove electrons from an atom is known as ionization energy. Therefore, the correct answer is ionization, as it directly relates to the process of removing electrons.

What is the name of family I

• Alkaline Earth Metals

• Boron Family

• Alkali Metals

• Halogen Family

Answer explanation

The correct answer is 'Alkali Metals' as it refers to Group 1 elements in the periodic table, which are known for their reactivity and include lithium, sodium, and potassium.