What is the primary difference between an element and a compound?

• An element is made of one type of atom, while a compound consists of two or more different atoms bonded together.

• An element can be found only in solid state, whereas a compound can be found in all states of matter.

• A compound is made of one type of atom, while an element consists of two or more different atoms bonded together.

• An element is always liquid at room temperature, whereas a compound is always solid.

Answer explanation

What process is used to separate a soluble solid from a liquid?

• Filtration

• Simple distillation

• Fractional distillation

• Chromatography

Answer explanation

Which statement best describes the movement of particles in gases compared to liquids and solids?

• Particles in gases move randomly and are far apart, unlike those in liquids and solids.

• Particles in gases do not move, unlike those in liquids and solids.

• Particles in gases vibrate only, similar to particles in solids.

• Particles in gases are arranged regularly and close together, unlike those in liquids.

Answer explanation

What is the maximum number of electrons that can be contained in the second shell of an atom?

• Two electrons

• Eight electrons

• Six electrons

• Four electrons

Answer explanation

What is the role of chromatography in separating mixtures?

• It separates mixtures based on the boiling points of components.

• It separates mixtures based on the solubility of components in a solvent.

• It separates colors in a mixture by allowing them to travel at different speeds on a paper.

• It separates mixtures by cooling them rapidly.

Answer explanation

What is the charge of a neutron?

• A) +1

• B) 0

• C) -1

• D) +2

Answer explanation

protons = +1 charge

electron = -1 charge

no particle has +2 charge

Which group in the periodic table is known for being highly reactive and contains elements that react vigorously with water?

• A) The noble gases

  Group 0

• B) The halogens

  Group 7

• C) The alkali metals

  Group 1

Answer explanation

The halogens are also highly reactive but they don't react with water.

The noble gases are all very unreactive

What is the electronic configuration of magnesium?

• A) 2, 8, 2

• B) 2, 8, 1

• C) 2, 7, 2

• D) 2, 8, 0

Answer explanation

magnesium is in period 3 so it has 3 shells

the first two are full - 2 then 8

it is in Group 2 so has 2 electrons in its outer shell

therefore it must be 2, 8, 2

What are the products of the reaction when mixing hydrochloric acid and magnesium?

• A) Magnesium chloride + hydrogen

• B) Magnesium hydroxide + water

• C) Magnesium sulfate + water

• D) Magnesium carbonate + carbon dioxide

Answer explanation

What is the formula of an ammonium ion?

• A) NH₃⁺

• B) NH₄⁺

• C) NO₃^-

• D) NH₃