Abundance of Elements

Q.

Name and symbols of all element?

Q.

The most abundant metal present in the Earth's crust is ____.

1. O

2. Al

3. Fe

4. Cu

Q. Metal X is found in earth's crust. This metal forms a reddish brown substance when exposed to moist air. When a blue colored solution Y is stored in a container made of X, the solution turns green and a reddish brown metal Z gets deposited on the container.
X, Y and Z are respectively:

1. $Cu,CuS{O}_4,Fe$
2. $Zn,ZnS{O}_4,Fe$
3. $Fe,CuS{O}_4,Cu$
4. $Cu,FeS{O}_4,Fe$

Q. What is concentration of ore?

Q. ____ is defined as the process of getting rid of the unwanted rocky material from the ore.

1. Concentration
2. Purification
3. Dressing
4. All of the above

Q.

Two metals that exist in the free state?

Q.

Which of the following factors does economics of extraction depends on?

1. Use of metals

2. Availability of ores

3. Cost

4. All of the above

Q.

(a) Name the three classes in which elements are classified. Which was the first metal used by man?

(b) Name the metal and non-metal present in abundance in the earth crust.

Q. Which of the following metals are moderately reactive in nature?
(i) Zinc (ii) Gold
(iii) Sodium (iv) Iron

1. (ii) and (iii)
2. (i) and (iii)
3. Only (ii)
4. (i) and (iv)

Q.

For which ore of the metal, froth floatation method is used for concentration?

1. Horn silver

2. Bauxite

3. Cinnabar

4. Haematite

Q. Arrange the following elements in the order of their abundance in Earth's crust.

Aluminium - $Al$, Silicon - $Si$, Oxygen - $O$, Iron - $Fe$.

1. $Al>O>Fe>Si$
2. $O>Al>Fe>Si$
3. $O>Si>Al>Fe$
4. $O>Al>Si>Fe$

Q.

Concentration is also called “Ore dressing” or “Benefaction”. True or False?

1. True

2. False

Q.

Which is the most abundant metal in earths crust?

1. copper

2. zinc

3. gold

4. mercury

Q.

Which of the following factors does economics of extraction depends on?

1. Use of metals

2. Availability of ores

3. Cost

4. All of the above

Q.

The most abundant metal present in the Earth's crust is ____.

1. copper

2. iron

3. oxygen

4. aluminium

Q. The impurities present in mined ores are technically calledand the process of removing them from the ore is calledof an ore.

1. gangue
2. flux
3. concentration
4. metallurgy

Q. Question 1 (ii)
Give an example of a metal which can be easily cut with a knife.

Q.

Why should the ore be concentrated? Give reason.

Q.

Write the uses of gold, mercury and zinc. [3 MARKS]

Q.

The unwanted and valueless part for which the concentration of ore done is _________.

1. Matrix

2. Slag

3. Waste

4. Gangue

Q. Arrange the followings in their increasing order of the metallic-properties:- A) Na , B) Mg , C) B , D) Al .

Q. The impurities present in mined ores are technically calledand the process of removing them from the ore is calledof an ore.

1. gangue
2. flux
3. concentration
4. metallurgy

Q. Silicon is the 2nd abundunt element in the earth's crust.

1. False
2. True

Q. Some low reactive metals exists as sulphide ores too.

1. True
2. False

Q. Arrange the following elements in the order of their abundance in Earth's crust.

Aluminium - $Al$, Silicon - $Si$, Oxygen - $O$, Iron - $Fe$.

1. $Al>O>Fe>Si$
2. $O>Al>Fe>Si$
3. $O>Si>Al>Fe$
4. $O>Al>Si>Fe$

Q. Explain the difference between dressing of ore and concentration of ore

Q.

Which of the following factors does economics of extraction depends on?

1. Use of metals

2. Availability of ores

3. Cost

4. All of the above

Q.

Arrange the following elements in the order of their abundance in Earth's crust:

Aluminium - $Al$, Silicon - $Si$, Oxygen - $O$, Iron - $Fe$.

1. $Al>O>Fe>Si$
2. $O>Al>Fe>Si$
3. $O>Al>Si>Fe$
4. $O>Si>Al>Fe$