Science Matters

Dr. Hayes loves to make a lot of different kinds of breads. She remembers learning about chemical changes and mixtures/solutions in science. She wonders, when she makes bread, what is she making?

• Solution

• Mixture

What happens to salt when mixed in water?

• it forms a solution

• nothing happens

• it floats

• it expands

Which statement describes a property of air that can be used to explain the difference in the shapes of the balloon?

• Air cannot be trapped in a small space.

• Air particles cannot be forced to stay inside a balloon.

• Air does not have a definite shape and expands to fill a space.

• Air will always have a round shape when it is trapped in a balloon.

How does changing the state of a substance affect its mass?

• Mass decreases

• Mass increases

• Mass remains the same

• There is no mass

Particles that are closely packed together is a _________.

• Solid

• Liquid

• Gas

• Chemical

Particles that are separated with very little attraction between them is a ______________.

• Solid

• Liquid

• Gas

• Chemical

Particles that can move pass each other easily is a ____________.

• Solid

• Liquid

• Gas

• Chemical

What makes sea water a mixture? Select two answers.

• The water and salt can be separated by evaporation.

• People use boats to stir the water.

• The salt and other elements cannot be separated.

• The other elements in the ocean (plants, animals, salt, colt) can be separated.

When water changes from solid to liquid, what changes and what stay the same?

• STATE changes but the MASS stays the same.

• MASS changes but STATE stays the same.

Dr. Hayes was conducting an investigation to see if ice cubes in water are a mixture or a solution. What should Dr. Hayes' hypotheses be?

• Ice cubes in water are only a mixture because it can be removed.

• Ice cubes melt so it is a solution.

• The physical properties of water can be liquid or a solid so it is a mixture and solution depending on temperature.

• Ice cubes in water turn into a different substance.