Chemistry

Question 1

Cathode rays were discovered by ____.

Answer 1

Julius Plucker

Question 2

Who discovered the neutron?

Answer 2

Chadwick

Question 3

Only atom where neutrons are not present.

Answer 3

Hydrogen

Question 4

Atomic number is equal to the number of protons / neutrons?

Answer 4

Protons

Question 5

Formula for atomic mass

Answer 5

Atomic number + no. of neutrons

Question 6

Lightest isotope

Answer 6

Hydrogen

Question 7

Heaviest isotope

Answer 7

Lead

Question 8

Who coined the term ‘radioactivity’?

Answer 8

Marie Curie

Question 9

Radioactivity is measured by ____.

Answer 9

Geiger measure

Question 10

Energy of the sun is a result of ___.

Answer 10

Nuclear fusion

Question 11

___ is used to determine the age of the earth, rocks, etc.

Answer 11

Uranium dating

Question 12

Which radioisotope is used for brain imaging?

Answer 12

Iodine-123

Question 13

Which radioisotope is used for treating cancer?

Answer 13

Cobalt-60

Question 14

This ion is formed when they lose an electron.

Answer 14

Cation

• Anion is when they gain an electron

Question 15

Sharing of electrons between two elements is a ____ bond.

Answer 15

Covalent

Question 16

Which metal has highest melting point?

Answer 16

Tungsten

Question 17

Metal with lowest density.

Answer 17

Lithium

Question 18

____ is used for artificial rain.

Answer 18

Silver iodide

Question 19

____ is a process that makes the surface of metals resistant to corrosion.

Answer 19

Anodisation

Question 20

___ is a natural plastic.

Answer 20

Lac

Question 21

Acid rain has a pH less than ___.

Answer 21

5

Question 22

Percent of calcium phosphate in bones.

Answer 22

57%