Question

What kind of change is rusting of iron and what kind of change is conversion of a compound into its elements?

a)Both are chemical changes

b) both are physical change

c)rusting of iron is physical change and conversion of a compound into its element is a chemical change.

-The scattering of a - particles b thin metal foils established that

a)electrons are fundamental particles of all mater

b)the mass of an atomis concentrated in a positively charged nucleus

c)atoms are electrically neutral

-Which of the following conclusions can be drawn from JJ Thomsons cathode ray experiment?

a)atoms contain protons, neutrons and electrons

b)practically all the mass of an atom is

c)atoms contain electrons

- Give an isotope of 12^C

a) 12^C 7

b) 13^C 7

c) 13^C 6

- Write the complete chemical symbol of the isotope of chlorine whose atoms have 20 neutrons.

a) 37^Cl 17

b) 37^Cl 18

c) 36^ Cl 18

- Identify the group number in the periodic table of X, a representative element, in the ionic compound, XCl3

a) 2

b)3

c) 4-

Represent the most stable ion of oxygen

a) O 2+

b)O 6-

c) O2

- An element's most stable ion formsan ionic compound with oxygens, having the formula MO. If the ion of element M has a mass number of 25 and 10 electrons, what is the identity of the element, and how many neutrons does it have?

a) The element is magnesium and it has 12 neutrons

b)The element is magnesium and has 25 neutrons

c) Magnesium and has 13 neutrons

- Give the formula of ionic compound

a) Potassium bromate

b)Sodium hypochlorite

- Name the formulas of the compounds

a)BaN2

b)kBr3

c)AlO2

d)MCl

Answer 1

What kind of change is rusting of iron and what kind of change is conversion of a compound into its elements?

a)Both are chemical changes

The scattering of a - particles b thin metal foils established that

b)the mass of an atom is concentrated in a positively charged nucleus

Which of the following conclusions can be drawn from JJ Thomson's cathode ray experiment?

c)atoms contain electrons

Give an isotope of 12^C

c) 13^C 6

Write the complete chemical symbol of the isotope of chlorine whose atoms have 20 neutrons.

a) 37^Cl 17

Identify the group number in the periodic table of X, a representative element, in the ionic compound, XCl3

b)3

Represent the most stable ion of oxygen

a) O 2+

An element's most stable ion forms an ionic compound with oxygens, having the formula MO. If the ion of element M has a mass number of 25 and 10 electrons, what is the identity of the element, and how many neutrons does it have?

c) Magnesium and has 13 neutrons

Potassium bromate -KBrO₃

Sodium hypochlorite-NaOCl

kBr3-Potassium tribromide

AlO2-Aluminium aluminate

MCl- Metal chloride