Elements, Compounds, Symbols And Formulae CHEMISTRY - Elements, Compounds, Symbols And Formulae

A group of atoms of elements

An element which is a poor conductor of heat

An impure substance

The element which is malleable

The negatively charged particles in an atom

Answer the following question:
Give the advantages of using symbols instead of names of elements or compounds.

Write the molecular formulae of compound lead sulphide.

Write the molecular formulae of compound hydrogen sulphide.

Write the molecular formulae of compound calcium oxide.

Elements are classified into – Metals – Non-metals – Metalloids – Noble gases. State which of A, B, C, D is a –

1. Metallic element
2. Non-metallic element
3. Metalloid
4. Noble gas.

A: Is non-malleable, non-ductile & a poor conductor of electricity ___________
B: Has lustre, is malleable and ductile & a good conductor of heat ___________
C: Is unreactive and inert and present in traces in the air _________
D: Shows properties of both metals and non-metals ___________

Differentiate between the terms –
elements, compounds & mixtures.

Give the names and symbols of the first twenty elements of the periodic table. Differentiate them into metals, non-metals, metalloids, and noble gases

Match the noble gases – with their correct symbols:

Noble gases	Symbols
(a) Helium	(1) Ar
(b) Neon	(2) Xe
(c) Argon	(3) Rn
(d) Krypton	(4) He
(e) Xenon	(5) Kr
(f) Radon	(6) Ne

Classify substances into pure and impure substances in the form of a chart or tabulation.

Match the statements in List I – 1 to 10 correct answers in List II-A to J.

	List I		LIst II
1	Fluorine and chlorine	A	Nitrogen
2	A diatomic molecule	B	Boron
3	A molecule containing the elements hydrogen and oxygen.	C	Reactants
4	A metalloid - showing properties of both metals and non-metals.	D	Chemical Formula
5	The term used for the substances which take part in the chemical reaction	E	Halogens
6	The term represents a substance by means of symbols.	F	Water
7	The term used for the substances formed as a result of a chemical reaction	G	Nitric Acid
8	A compound containing one atom of zinc and two atoms of chlorine.	H	Products
9	The chemical name for nitrogen monoxide.	I	Phosphorus
10	A polyatomic molecule.	J	Zinc Chloride

Match the non-metallic elements – with their correct symbols. Non-metallic elements are:

Non-Metallic elements	Symbol
(a) Carbon	(1) O
(b) Chlorine	(2) I
(c) Oxygen	(3) Si
(d) Phosphorus	(4) C
(e) Hydrogen	(5) Cl
(f) Nitrogen	(6) P
(g) Iodine	(7) F
(h) Bromine	(8) H
(i) Fluorine	(9) S
(j) Silicon	(10) Br
(k) Sulphur	(11) N

Match the metallic elements – with their correct symbols Metallic elements

Metallic elements	Symbol
(a) Potassium	(1) Ca
(b) Sodium	(2) Zn
(c) Calcium	(3) Pb
(d) Magnesium	(4) Hg
(e) Zinc	(5) Cu
(f) Aluminum	(6) Au
(g) Iron	(7) K
(h) Lead	(8) Fe
(i) Copper	(9) Al
(j) Mercury	(10) Na
(k) Silver	(11) Mg
(l) Platinum	(12) Pt
(m) Gold	(13) Ag

Find the atomicity of the Following molecule:
Carbon Monoxide

Find the atomicity of the Following molecule:
Dinitrogen Oxide

Find the atomicity of the Following molecule:
Acetic Acid

Find the atomicity of the Following molecule:
Aluminium Suiphide

Find the atomicity of the Following molecule:
Calcium Chloride

From the elements nitrogen, chlorine, bromine, the element present in the atmosphere is ________.

From the elements – He, Br, Pt, and O; the element which is metallic is ____, an inert element is ____, forms a triatomic molecule is ____, is liquid at room temperature is_ ___.

Element ______ has the symbol derived from its Latin name ‘Argentum’

Atom contains ________ , with positively charged _____.

The basic unit of an element is an __________.

Ozone is a triatomic molecule

Noble gases are high reactive

Molecules combine to form atoms

Molecules can exist independently

All elements are artificially prepared

Match the Columns:

	Column A		Column B
(a)	Metals	(i)	Non-Reactive
(b)	Molecules	(ii)	Brittle
(c)	Non-Metals	(iii)	Lustrous
(d)	Noble Gases	(iv)	Smallest unit of Compound