Question

Bhai sahi shai solve kr do 100 pts milenge......Chapter ka naam Matter and Chemical Formulae Class 7.....
A. Fill in the blanks.

1. Each element is represented by a chemical equation .

2. The number of atoms present in a molecule of an element is called its atomicity.

3. One formulae of water is made of two atoms of hydrogen and one atom of oxygen.

4. The of an element is defined as the combining capacity of an element.

5. The elements of compounds that react in a reaction are called _______________.

6. A chemical equation is a symbolic representation of a chemical ______________.



B. State whether the following are true or false.

1. The combining capacity of an element is called its valency. _______

2. Au is the chemical symbol for Iron. _______

3. An atom consists of only electrons and protons. _______

4. The chemical symbol for copper is derived from its Latin name cuprum. _______

5. Some elements can have more than one Valency. _______



C. Answer in one word.

1. Elements with atomicity two. ___________

2. Combining capacity of an element. ___________

3. Symbolic representation of a chemical reaction. ___________

4. The elements or compounds that form in chemical reactions. ___________



D. Match the following:

1. H2O ( ) a. Carbon Dioxide

2. NaOH ( ) b. Calcium Oxide

3. CaO ( ) c. Water

4. MgSO4 ( ) d. Sodium Hydroxide

5. CO2 ( ) e. Magnesium Sulphate



E. Answer the following:

1. What is a balanced chemical equation? Give an example.

_________________________________________________________________________________ _________________________________________________________________________________



2. What is valency? Write valancies of any two elements.

_________________________________________________________________________________

_________________________________________________________________________________

​

Answer 1

Answer:

I know only match the following

5

3

1

2

4

Is the match the following answer

Explanation:

H²O IS Water

CaO is calcium oxide

CO² is carbon dioxide

NaOH is sodium hydroxide

MgSO⁴ is magnesium sulphate