Question

Classify these properties of the metal lithium as physical or chemical. Physical Chemical light enough to float on water silvery gray in color changes from silvery gray to black when placed in moist air can be cut with a sharp knife in the liquid state, it boils at 1317 °C reacts violently with chlorine to form a white solid in the liquid state, it reacts spontaneously with its glass container, producing a hole in the container burns in oxygen with a bright red flame

Answer 1

The psychical properties do no change the composition of the lithium metal.

The chemical properties will change the composition of the lithium producing other substances.

light enough to float on water - physical property

silvery gray in color - physical property

changes from silvery gray to black when placed in moist air - chemical property

(in air the lithium will react with the oxygen forming the oxide which have a black color)

can be cut with a sharp knife - physical property

in the liquid state, it boils at 1317 °C - physical property

reacts violently with chlorine to form a white solid - chemical property

in the liquid state, it reacts spontaneously with its glass container, producing a hole in the container - chemical property

burns in oxygen with a bright red flame - chemical property

Answer 2

Explanation:

A property that does not bring any change in chemical composition of a substance are known as physical properties.

For example, shape, size, mass, volume, density, hardness etc of a substance are all physical properties.

On the other hand, a property that changes chemical composition of a substance is known as chemical property.

For example, precipitation, reactivity, toxicity etc are chemical property.

Hence, the given properties of lithium are classified as follows.

• Light enough to float on water - Physical

• silvery gray in color - Physical

• changes from silvery gray to black when placed in moist air - Chemical

• can be cut with a sharp knife - Physical

• in the liquid state, it boils at $1317^{o}C$ - Physical

• reacts violently with chlorine to form a white solid in the liquid state - Chemical

• it reacts spontaneously with its glass container, producing a hole in the container - Chemical

• burns in oxygen with a bright red flame - Chemical