MEDIUM
7th CBSE
IMPORTANT
Earn 100

Using the definitions, decide whether the following diagram represents an element, a compound, or a mixture. Explain your choice.

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Important Questions on Elements, Compounds and Chemical Equations

MEDIUM
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Assess>Q 1
Elements in our Earth's crust: 
Element  % by weight 
Oxygen  46.6
Silicon  27.7
Aluminium  8.1
Iron 5.0
Calcium  3.6
Sodium 2.8
Potassium 2.6
Magnesium 2.1
Others 1.5

Which is the second most abundant element in the earth's crust? Name some ores of that element? 

 

EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Assess>Q 2
Elements in our Earth's crust: 
Element  % by weight 
Oxygen  46.6
Silicon  27.7
Aluminium  8.1
Iron 5.0
Calcium  3.6
Sodium 2.8
Potassium 2.6
Magnesium 2.1
Others 1.5

Bauxite is the ore of which of the above mentioned elements?

EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Cyber Link>Q 1
Find out the elements that are named on the name of scientists who discovered them.
EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Explore>Q 1
Find out the number of atoms in a molecule of chlorine gas and sulphur.
EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Explore>Q 1
How will you separate the constituents of oil and water mixture?
MEDIUM
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Think Science>Q 1
Do iron loose its magnetic property if a mixture of iron nails and sulphur powder are taken? What if we heat this mixture?
EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Assess>Q 1

Write the chemical formula of

Aluminium oxide

EASY
7th CBSE
IMPORTANT
WOW! SCIENCE Hands-on Learning in SCIENCE 7>Chapter 6 - Elements, Compounds and Chemical Equations>Assess>Q 1

Write the chemical formula of Calcium oxide.