Question

please answer me it's very urgent​

Answer 1

Answer:

Explanation:

1)it is a physical change because the sugar can be brought back fro the water

2) some solids such as ice when heated changes into liquid through the process of convection

3)rusting of iron is a chemical change as we cannot bring back the iron and the chemical properties change.

4)

Answer 2

Answer:

i) no new substance is formed; two substances are just mixed togther in solution

ii) heating supplies energy

energy supplied breaks some bonds/weakens bonds between solid particles and separates them slightly, giving them a random structure and allowing each particle to move around another particle

iii) iron reacts with oxygen and water to form a new substance - rust (iron(III) oxide)

iv) a mixture which has uniform composition throughout its mass is called homogeneous mixture

sodium chloride is uniformly dissolved in water, completely

v) most of the atom is empty space

the nucleus is very tiny

most alpha particles dont even pass close to the positive nucleus

hope it helps:)