CHEMISTRY [1 Mark Question Answer]

Atomicity of

Carbon Monoxide - CO
= 1 X 1 + 1 X 1 = 1 + 1= 2

When iron is mixed with sulphur at room temperature, it does not form a compound because the mixture of iron and sulphur requires heat to form a compound i.e. iron sulphide.

Metals are ductile, i.e., they can be drawn or stretched into thin wires.
They are malleable, i.e., they can be beaten into thin sheets.

Copper and aluminium are good conductors of heat and electricity. They can be drawn into wires and beaten into sheets. Therefore, they are used to make electric wires.

Argon is an inert gas and protects the element of bulb from oxidation and burning. Hence increases bulb’s life.

Graphite leaves mark on the paper and makes it black.

Steel is a good conductor of heat to cook food, the pan is made of steel whereas wood is an insulator of heat, and to hold, handle is made up of wood.

Coal: Coal is used as fuel also used in thermal power plants to produce electricity.

Brass: To make water taps and utensils.

Iron : To make machines tools and building material.

Plastic is used as insulator as it is bad conductor of electricity

Two substances used to make jewellery are:
1.Gold.
2. Silver as these are shining, lustrous, and ductile.

Two substances used to make electric wires are:
1. Copper.
2. Aluminium as these are good conductors of electricity.

Diamond is used as a gem.

Three different forms of carbon are:
1. Diamond
2. Graphite
3. Coal

Compound Carbon Monoxide is compound of elements Carbon (C) and Oxygen (O).

Formula of Carbon Monoxide id CO

A formula gives us the following information about a compound.

1. Types of elements present in the compound.
2. A number of each kind of atoms in one molecule of the compound.
3. Mass of one molecule of the compound

Formula: Formula is a short way of representing the molecule of an element or a compound

Atomicity: The number of atoms in a molecule of an element is called its atomicity.

Molecule: A molecule can be defined as the smallest unit of an element or a compound which exhibits all the properties of that element or compound and has an independent existence. They are divisible into atoms.

Examples of Noble gases are Helium, argon, neon

Examples of Metalloids are Antimony, silicon, boron

Examples of Non-metals: Carbon are sulphur, oxygen.

Metals: Iron, silver, gold

Carbon is C, Chlorine is Cl, Calcium is Ca, Cobalt is Co Copper is Cu, Argon is Ar.

Two compounds which dissolve in water are sugar, table salt.

Elements present in Washing soda:
Sodium, carbon & oxygen

Elements present in Marble:
Calcium, carbon & oxygen

Elements present in Ammonia:
Nitrogen and hydrogen

Elements Present in Sugar:
Carbon, hydrogen & oxygen

Examples of Metalloids are Antimony, silicon, boron

Helium, Neon

Mercury, Bromine

Radium, Graphite

Lead and Sodium

Phosphorus, Sulphur

Element: Mercury, sulphur, gold, coal, oxygen.
Compound: Sugar, water, sand, alcohol.

A poisonous gas almost as heavy as air is Carbon monoxide

A gas with a pungent, choking odour which is lighter than air is Ammonia

(i) Chlorine – greenish-yellow

(ii) Nitrogen dioxide – reddish brown.