Element,compound & mixture

Question 1

What are homogenous and heterogenous mixture?

Answer 1

Homogenous mixture- uniform composition and visually the same throughout

Heterogenous- not uniform composition, composition that varied from point to point,visible with naked eyes

Question 1

What are pure substances and mixture?

Answer 1

Pure substances- element and compounds

Mixture- composition of two or more different matter and can be separated by physical changes

Question 2

What is a pure substance?

Answer 2

Matter with the same composition and same properties.

Question 3

What are the types of pure substances?

Answer 3

Elements and Compounds.

Question 4

What is an element?

Answer 4

A substance that cannot be broken down into simpler substances (e.g., Chlorine, Sodium, Carbon).

Question 5

What is a compound?

Answer 5

A substance that can be broken down into elements or other compounds by chemical reaction (e.g., Sodium chloride, Glucose).

Question 6

What is a mixture?

Answer 6

Matter containing two or more substances that can be separated by physical means (e.g., evaporation, distillation).

Question 7

What is a heterogeneous mixture?

Answer 7

A mixture with a composition that varies from point to point (e.g., salad, sand & sugar).

Question 8

What is a homogeneous mixture?

Answer 8

A mixture with uniform composition, also known as a solution (e.g., air, vinegar).

Question 9

Unsaturated solution

Answer 9

Less solute than solvent in solution (more solute can dissolved)

Question 10

Saturated solution

Answer 10

Max amount of solute is solution (no more solute can dissolved)

Question 11

Supersaturated solution

Answer 11

More solute than solvent in the solution (excess solute are precipitated)

Question 12

Soluble solid gets more soluble as _______.

Answer 12

Temperature increases

Question 13

A pure substance have definite,sharp melting point & boiling point.True or False?

Answer 13

True

Question 14

Total elements

Answer 14

118 elements
91 natural elements & 27 man-made elements

Question 15

Properties of metal

Answer 15

1)High bp
2)High mp
3)High density
4)Mellability & ductility
5)Good conductor

Question 16

Properties of nonmetal

Answer 16

1)Low bp
2)Low mp
3)Low density
4)Brittle
5)Poor conductor

Question 17

Smallest atom is _______.

Answer 17

Hydrogen atom

Question 18

Element is made up of_______.

Answer 18

one kind of atom

Question 19

Elements can be classified as _____ & ______.

Answer 19

metals
nonmetals

Question 20

Matter are made up of _______.

Answer 20

tiny particles called atoms/molecules

Question 21

Atom

Answer 21

Smallest unit of element

Question 22

Molecule

Answer 22

Two or more atom which are chemically bonded together

Can be atom of same or different elements

Question 23

Diatomic molecules

Answer 23

Nonmetals atoms which are exist as diatomic molecules
eg.O2,Cl2,I2

Question 24

Monoatomic molecule

Answer 24

Noble gases They have stable octet structure

Question 25

All molecules are elements.True or False?

Answer 25

False Only the molecules of same atom are elements. Monoatomic and diatomic molecules are also elements.

Question 26

In compound,elements are combined ______ in ______.

Answer 26

Chemically in fixed ratio eg.H2O

Question 27

In mixture,two or more substance are mixed in fixed ratio.True or False?

Answer 27

False not in fixed ratio

Question 28

Property of mixture is the same as the property of original substance.True or False?

Answer 28

True

Question 29

Homogenous or heterogenous mixture alloy blood Air Smoke Sand & Water

Answer 29

Alloy-homo blood-hetero Air-homo smoke-hetero Sand & water-hetero

Question 30

Homogenous or heterogenous? Blood Vinegar Gasoline Bronze Metals

Answer 30

Heterogenous Homo Homo Homo Homo

Question 31

What is an element?

Answer 31

An element is made up of one kind of atom and that cannot be broken down into other substances chemical reactions

Question 32

Do artificial elements are stable?

Answer 32

No,30 artificial are produced in lab and they are very unstable

Question 33

What is compound?

Answer 33

A substance made by two or more elements with fixed proportions .It has different properties from its elements