Periodic Trends

Q. Periodic table :- chemistry

why reactivity decreases down down the group in non metals (17th group) ?

Q.

Is conductivity a physical property or a chemical property?

Q.

How could the modern periodic table remove various anomalies of Mendleev‘s periodic table? [3 MARKS]

Q.

Analyse the options given below and choose an element with the largest atomic radii.

1. Neon

2. Fluorine

3. Lithium

4. Berrylium

Q.

Which among the following has the maximum electron affinity?

1. Chalcogens

2. Alkali Metals

3. Noble Gases

4. Halogens

Q. Choose the correct reason for the following statement.
"In the modern periodic table, nitrogen is placed just before oxygen in the second period."

1. Oxygen has smaller atomic radius than nitrogen.
2. Oxygen is more electronegative than nitrogen.
3. Oxygen has one more proton in its nucleus than nitrogen.
4. The given statement is false.

Q.

The statement that is not correct for the periodic classification of elements is :

1. The properties of elements are the periodic functions of their atomic numbers

2. Atomic size in a period decreases as we move from left to right

3. The first ionization energies along a period do not vary in a regular manner with increase in atomic number

4. The transition elements occupy groups 3-12.

Q.

Why does reactivity increase down the group?

Q.

The Electron Gain Enthalpy decreases with increase in Atomic Number.

1. False

2. True

Q.

Which of the following pairs are chemically dissimilar?

1. Na, K

2. B, Al

3. Be, Mg

4. Ca, Cu

Q.

Why Zinc is a soft metal?

Q.

The electronic configuration of halogen is

1. $n{s}^2$

2. $n{s}^{2}n{p}^3$

3. $n{s}^{2}n{p}^5$

4. $n{s}^{2}n{p}^6$

Q. Match the elements with the block they belong to in the modern periodic table.

1. s-block
2. p-block
3. d-block
4. f-block

Q. What is the chemical formula of aluminium chloride?

1. $AlC{l}_3$
2. $AlC{l}_2$
3. $A{l}_{2}C{l}_3$
4. $AlCl$

Q. Elements achieve octet configuration by-

1. Gaining electrons
2. Losing electrons
3. Sharing electrons
4. Creating electrons

Q.

Which element forms maximum compounds in chemistry

1. O

2. Si

3. C

4. H

Q. Why are most elements not found in the free state in nature?

Q. Assertion :Elements in the same vertical column have similar properties. Reason: Elements have periodic dependence upon the atomic number.

1. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion
2. Both Assertion and Reason are correct, but Reason is not the correct explanation of assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q.

When an electron jumps from L (n=2) to K (n=1) shell ___ is released.

Q.

Identify the properties that directly depend on the electronic configuration of an atom.

1. Valency

2. Ionisation energy

3. Electron gain enthalpy

4. Electronegativity

Q. Why does oxygen accept a pair of electrons instead of donating one electron so as to become half filled (1s^2, 2s^2, 2p^3) ? Isnt it easier to give one that to take two?

Q.

Consider the following statements:

(I) The radius of an anion is larger than that of the parent atom.
(II) The ionization enthalpy generally increases with increasing atomic number in a period.
(III) The electronegativity of an element is the tendency of an isolated atom to attract an electron.

Which of the above statements is/are correct?

1. I alone

2. II alone

3. II and III

4. I and II

Q. Question 15
Which of the following elements does not lose an electron easily?

(a) Na
(b) F
(c) Mg
(d) Al

Q.

Which of the following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens is correct?

1. Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens.

2. In alkali metals the reactivity increases but in the halogens it decreases with increase in atomic number down the group.

3. The reactivity decreases in the alkali metals but increases in the halogens with increase in atomic number

4. In both the alkali metals and the halogens, the chemical reactivity decreases with increase in atomic number down the group.

Q.

why fe has valency 2 however its electronic configuration has 4 unfilled orbitals

Q.

Assertion: Elements with the same chemical properties are kept in the same group.

Reason: Elements in a group have the same number of electrons in the outermost shell hence they have similar chemical properties.

1. Both assertion and reason are true and the reason is the correct explanation for the assertion.

2. Both assertion and reason are true but the reason is not the correct explanation for the assertion.

3. The assertion is false but the reason is true.

4. The assertion is true but the reason is false.

Q. Which one of the following is the most electropositive element?

1. Sodium
2. Calcium
3. Aluminium
4. Silicon

Q.

Which of the following pairs are chemically dissimilar?

1. Na, K

2. B, Al

3. Be, Mg

4. Ca, Cu

Q.

Assertion: Elements in the same column have similar properties.
Reason: Periodic properties of elements is a function of atomic number.

1. Both assertion and reason are true and reason is the correct explanation of assertion

2. Both assertion and reason are true and reason is not the correct explanation of assertion

3. Assertion is true but reason is false

4. Both assertion and reason are false