Periodic Properties and Variation in Properties

Question 1

State the number of elements in Period 1, Period 2 and Period 3 of the Periodic Table.

Answer 1

There are 2 elements in Period 1 and 8 elements in each of Period 2 and Period 3.

Question 2

Name the elements in Period 1.

Answer 2

Hydrogen and Helium.

Question 3

What happens to atomic size of elements on moving from left to right in a period?

Answer 3

The atomic size of elements on moving from left to right in a period decreases.

Question 4

What is the common feature of the electronic configuration of the elements at the end of Period 2 and Period 3?

Answer 4

The atoms of the elements at the end of Period 2 and Period 3 has 8 electrons in their outermost shell.

Question 5

If an element is in group 7 (or group 7A), is it likely to be metallic or non- metallic in character?

Answer 5

Non-metallic.

Question 6

If an element has one electron in its outermost energy level, then it is likely to be ________ (metallic/non-metallic).

Answer 6

Metallic

Question 7

The properties of the elements are a periodic function of their ___________ (atomic number, mass number, relative atomic mass)

Question 8

Moving across a ___________ of the Periodic Table, the elements show increasing ___________ character (group, period, metallic, non-metallic)

Answer 8

period, non-metallic

Question 9

The elements at the bottom of a group would be expected to show __________ metallic character than the element at the top (less, more)

Answer 9

more

Question 10

What is meant by a Group in the Periodic Table?

Answer 10

The vertical column in a periodic table are called group.

Question 11

The similarities in the properties of a group of elements is because they have the same __________ (atomic number, electronic configuration, number outer electrons).

Answer 11

number of outer electrons

Question 12

Within a group where would you expect to find the element with:
(a) the greatest metallic character? (b) the largest atomic size?

Answer 12

(a) At the bottom of the group. (b) At the bottom of the group.

Question 13

State whether the ionization potential increases or decreases on going down a Group.

Answer 13

Decreases

Question 14

How many elements are there in Period 2?

Answer 14

Eight

Question 15

Write the formula of the sulphate of the element with atomic number 13.

Answer 15

Al₂(SO₄)₃

Question 16

What type of bonding will be present in the oxide of the element with atomic number 1?

Answer 16

Covalent

Question 17

Which features of the atomic structure accounts for the similarities in the chemical properties of the elements in group 7A of the periodic table?

Answer 17

All the elements of the group 7A contain 7 valence electrons in their outermost shell. All of them require one electron to complete their octet.

Question 18

Name the elements which has the highest ionization potential.

Answer 18

Helium

Question 19

How many electrons are present in the valency shell of the element with the atomic number 18?

Answer 19

8 electron

Question 20

What is the name given to the energy released when an atom in its isolated gaseous state accepts an electron to form an anion?

Answer 20

Electron affinity

Question 21

What is the electronic configuration of the element in the third period which gains one electron to change into an anion?

Answer 21

2, 8, 8

Question 22

The atomic size ________ as we move from left to right across the period, because the __________ increases but the __________ remains the same.

Answer 22

decreases, nuclear charge, number of shells

Question 23

The electro-negativities (according to Pauling) of the elements in period 3 of the Periodic Table are as follows with the elements arranged in alphabetical order:

Al Cl Mg Na P S Si
1.5 3.0 1.2 0.9 2.1 2.5 1.8

Arrange the elements in the order in which they occur in the Periodic Table from left to right. (The group 1 element first, followed by the group 2 element and so on, up to group 7.)

Answer 23

Na, Mg, Al, Si, P ,S, Cl

Question 24

The electro-negativities (according to Pauling) of the elements in period 3 of the Periodic Table are as follows with the elements arranged in alphabetical order:

Al Cl Mg Na P S Si
1.5 3.0 1.2 0.9 2.1 2.5 1.8

The element below sodium in the same group would be expected to have a ______ (lower/higher) electro-negativity than sodium and the element above chlorine would be expected to have a _________ (lower/higher) ionization potential than chlorine

Answer 24

lower, higher

Question 25

The electro-negativities (according to Pauling) of the elements in period 3 of the Periodic Table are as follows with the elements arranged in alphabetical order: Al Cl Mg Na P S Si 1.5 3.0 1.2 0.9 2.1 2.5 1.8 On moving from left to right in a given period, the number of shells (remains the same/increases/decreases).

Answer 25

remains the same

Question 26

The electro-negativities (according to Pauling) of the elements in period 3 of the Periodic Table are as follows with the elements arranged in alphabetical order: Al Cl Mg Na P S Si 1.5 3.0 1.2 0.9 2.1 2.5 1.8 On moving down a group, the number of valence electrons (remains the same/increases/decreases).

Answer 26

remains the same

Question 27

Parts (i) to (v) refer to changes in the properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from the choices a, b, c and d. (i) The non-metallic character of the elements: (a) decreases (b) increases (c) remains the same (d) depends on the period.

Answer 27

(b) increases

Question 28

Parts (i) to (v) refer to changes in the properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from the choices a, b, c and d. The electro-negativity: (a) depends on the number of valence electrons (b) decreases (c) remains the same (d) increases.

Answer 28

(d) increases

Question 29

Parts (i) to (v) refer to changes in the properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from the choices a, b, c and d. The ionization potential: (a) goes up and down (b) decreases (c) increases (d) remains the same.

Answer 29

(c) increases

Question 30

Parts (i) to (v) refer to changes in the properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from the choices a, b, c and d. The atomic size: (a) decreases (b) increases (c) remains the same (d) sometimes increases and sometimes decreases.

Answer 30

decreases

Question 31

Parts (i) to (v) refer to changes in the properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from the choices a, b, c and d. The electron affinity of the elements in group 1 to 7: (a) goes up and then down (b) decreases and then increases (c) increases (d) decreases.

Answer 31

(a) goes up and then down

Question 32

The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne To which period do these elements belong?

Answer 32

second period

Question 33

The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne One element of this period is missing. Which is the missing element and where should it be placed?

Answer 33

nitrogen (N) is missing. This element should be placed between carbon and oxygen

Question 34

The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne Which one of the elements in this period shows the property of catenation?

Answer 34

carbon (C) shows the property of catenation

Question 35

The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne Place the three elements fluorine, beryllium and nitrogen in the order of increasing electro-negativity.

Answer 35

beryllium, nitrogen and fluorine

Question 36

The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne Which one of the above elements belongs to the halogen series?

Answer 36

fluorine (F).

Question 37

A group of elements in the Periodic Table are given below (Boron is the first member of the group and Thallium is the last): Boron, Aluminium, Gallium, Indium, Thallium. Which element has the most metallic character?

Answer 37

Thallium

Question 38

A group of elements in the Periodic Table are given below (Boron is the first member of the group and Thallium is the last): Boron, Aluminium, Gallium, Indium, Thallium. Which element would be expected to have the highest electro-negativity?

Answer 38

Boron

Question 39

A group of elements in the Periodic Table are given below (Boron is the first member of the group and Thallium is the last): Boron, Aluminium, Gallium, Indium, Thallium. If the electronic configuration of Aluminium is 2, 8, 3 how many electrons are there in the outer shell of Thallium?

Answer 39

3

Question 40

A group of elements in the Periodic Table are given below (Boron is the first member of the group and Thallium is the last): Boron, Aluminium, Gallium, Indium, Thallium. The atomic number of boron is 5. Write the chemical formula of the compound formed when Boron reacts with Chlorine.

Answer 40

BCl₃

Question 41

A group of elements in the Periodic Table are given below (Boron is the first member of the group and Thallium is the last): Boron, Aluminium, Gallium, Indium, Thallium. Will the elements in the group to the right of this Boron group be more metallic or less metallic in character? Justify your answer.

Answer 41

Less metallic due to increase in ionization energy