Question

1. a) which state of matter has a definite shape and a definite volume? ______

b) which state of matter has a indefinite shape and a definite volume? ______

1. a) a reaction that release energy is ______

b) a reaction that absorbs energy is ______

1. state if the following are physical or chemical properties:

a) density b) volume c) flammability d) color e) reacts with acid f) solubility

Explanation:

9a)

In the states of matter, solids have particles closely packed in a fixed arrangement, giving them a definite shape and definite volume. Liquids take the shape of their container (indefinite shape) but have definite volume, and gases have neither definite shape nor volume. So the state with definite shape and volume is solid.

9b)

Liquids have particles that are close together but can move past each other. This allows them to flow and take the shape of the container they are in (indefinite shape) but they maintain a definite volume (the amount of liquid doesn't change its volume unless added/removed). Gases have indefinite shape and volume, solids have definite both. So the state with indefinite shape and definite volume is liquid.

10a)

Reactions can be classified based on energy change. Exothermic reactions release energy (in the form of heat, light, etc.) into the surroundings. For example, combustion reactions (like burning wood) release heat. Endothermic reactions absorb energy. So a reaction that releases energy is exothermic.

10b)

Endothermic reactions absorb energy from the surroundings. For example, photosynthesis in plants absorbs light energy from the sun to convert carbon dioxide and water into glucose and oxygen. Exothermic releases energy, so a reaction that absorbs energy is endothermic.

11a)

Density is a physical property because it can be measured without changing the chemical identity of the substance. For example, we can measure the density of water (mass per unit volume) and it remains water, no chemical change occurs. Physical properties are about the physical characteristics (like color, density, volume, solubility) that don't involve changing the substance's chemical composition.

11b)

Volume is a physical property as it describes the amount of space a substance occupies. Measuring the volume of a liquid or a solid doesn't change what the substance is chemically. For example, the volume of a block of iron can be measured by displacement, and the iron remains iron.

11c)

Flammability is a chemical property because it describes the ability of a substance to undergo a chemical reaction (combustion) with oxygen (usually) to produce new substances (like carbon dioxide, water, etc. when burning a hydrocarbon). To test flammability, the substance has to burn, which is a chemical change.

11d)

Color is a physical property because it can be observed without changing the chemical nature of the substance. For example, the color of copper is reddish - brown, and we can see this without causing a chemical reaction to the copper.

11e)

"Reacts with acid" is a chemical property because when a substance reacts with an acid, a chemical reaction occurs, producing new substances. For example, when zinc reacts with hydrochloric acid, it produces zinc chloride and hydrogen gas. This involves a chemical change in the zinc.

11f)

Solubility is a physical property because it describes how much of a substance can dissolve in a solvent (like water dissolving salt) without changing the chemical identity of the solute or solvent. For example, dissolving salt in water: the salt can be recovered by evaporation (a physical process), and the salt and water remain chemically the same (salt is NaCl, water is H₂O before and after dissolving, except for the ionic separation which is a physical change in state of the solute).

Answer:

9a) Solid
9b) Liquid
10a) Exothermic
10b) Endothermic
11a) Physical property
11b) Physical property
11c) Chemical property
11d) Physical property
11e) Chemical property
11f) Physical property