Science Quiz – Matter, Properties, Changes, Density

What’s the difference between physical and chemical changes?

Physical = no new substance; Chemical = new substance forms.

Why is water a compound, not an element?

Because it has more than one atom type (H + O) chemically combined.

What’s the difference between a mixture and a compound?

Mixture = physical combo, easily separated; Compound = chemical combo, only separated chemically.

Give an example of a homogeneous mixture.

Salt water, air, steel.

Give an example of a heterogeneous mixture.

Salad, trail mix, oil + water.

True.

T/F: Mass and volume are examples of physical properties.

False (that describes a physical property).

T/F: A chemical property can be observed without changing a substance into a new one.

 False (needs chemical changes).

T/F: A compound can be broken down into simpler substances by physical changes. 

True.

T/F: Solutions are homogeneous mixtures.

False (physical).

T/F: Melting ice into water is a chemical change.

False (some are heterogeneous).

T/F: All mixtures are homogeneous.

True.

T/F: Elements cannot be broken down by chemical means.

False (its homogeneous).

T/F: A solution is a type of heterogeneous mixture.

What is a physical property?

A characteristic observed without changing the substance (e.g., color, density, melting point).

What is a chemical property?

A characteristic that describes how a substance reacts/changes into a new one (e.g., flammability, rusting).

Is “boiling point” a physical or chemical property?

Physical.

Is “reacts with acid” a physical or chemical property?

Chemical.

What are the 8 main physical properties?

Color, odor, texture, lustre, melting point, boiling point, density, solubility.

What is a physical change?

A change that alters form/appearance but does not make a new substance (e.g., melting, cutting paper).

What is a chemical change?

A change that produces a new substance with new properties (e.g., burning, rusting).

Is dissolving sugar in water physical or chemical?

Physical (no new substance).

Is baking a cake physical or chemical?

Chemical (new substances form).

What is the formula for density?

Density = Mass ÷ Volume.

If a block has mass 60 g and volume 20 mL, what is its density?

3 g/mL.

If an object has density less than water (1 g/mL), will it float or sink?

Float.

How can density identify an unknown substance?

Each substance has a unique density; compare your value to known ones.

What are the two main categories of matter?

Pure substances and mixtures.

What are the two types of pure substances?

Elements and compounds.

What is an element?

A pure substance made of one type of atom (e.g., oxygen, gold).

What is a compound?

A pure substance made of two+ elements chemically combined (e.g., water, carbon dioxide).

What are the two types of mixtures?

Homogeneous (solutions) and heterogeneous mixtures.

What is a solution?

A homogeneous mixture where substances are evenly mixed (e.g., salt water, air).

What is a heterogeneous mixture?

A mixture where substances are not evenly mixed, visible differences (e.g., salad, sand + water).

Classify oxygen gas.

Element.

Classify carbon dioxide.

Compound.

Classify salt water.

Homogeneous mixture (solution).

Classify a chocolate chip cookie.

Heterogeneous Mixture.

Classify gold.

Element.

Classify rust (Fe₂O₃).

Compound.

Is air a compound, solution, or heterogeneous mixture?

Solution (homogeneous gas mixture).