Question

please solve this chemistry problem​

Answer 1

Explanation:

1) Symbol represents the short form of a/an

a) molecule

b) element ✔

c) compound

d) radical

Explaination :-

In periodic table elements have its own symbol.

Like Sliver (Ag), Gold (Au), Platinum (Pt), etc.

2) Chemical formula is the symbolic representation of actual number of atoms present in one ___ of a substance

a) compound ✔

b) element

c) molecule

d) radical

Explaination :-

Chemical formula of Calcium carbonate is CaCO3 which represents actual number of atoms i.e, Ca, C, O present in one compound of a substance.

3) When an element exists as a molecule which consists two or more

a) ions

b) radicals

c) atoms ✔

d) Valency

Explaination :-

Two or more element combine together to make a molecule or compound.

4) The chemical formula of Calcium chloride is

a) CaCl

b) Ca2Cl

c) CaCl2 ✔

d) Ca2Cl2

Explaination :-

The Valency of Ca is 2 and Chlorine is 1

After Criss-crossing it form compound CaCl2 i.e, Calcium chloride.

5) A substance which doesn't take part in a chemical reaction, but change the rate of chemical reaction, is called :

a) reactant

b) active element

c) excited element

d) catalyst ✔

Explaination :-

Catalyst is used in Chemical reaction to make the chemical reaction fast or slow.

Like MnO2, H2O2.

Answer 2

Answer:

element

compound

iron

caocl2

catalyst

Explanation:

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