Science Water Unit Study Guide

Science Water Unit Study Guide

On Wednesday, November 23 the students will be taking a test on our science water unit. The words in the Word Bank are important to know as well as the bolded words.

Word Bank

property / expands / dome / absorbed / beads
contracts / sink / float / flow / surface tension
slope / water vapor / condenses / water cycle / thermometer
surface area

1. A property is a characteristic of a material or an object, something that you can observe such as color, smell, and taste.

1. When water soaks into another material, it is absorbed.

1. Water beads up on some materials.

1. Surface tension is the skinlike surface on water (and other liquids) that pulls it together into the smallest possible area (sphere).

1. A dome is the shape a drop of water takes when it is on a flat surface. It is like a flattened hemisphere.

1. A slope is a slanted surface.

1. Flow describes the movement of a liquid over a surface.

1. When water is heated, it expands to take up more space.

1. When water is cooled, it contracts to take up less space.

1. Materialssink in water if they are denser than water.

1. Materials float in water if they are less dense than water.

1. Liquid water changes into a gas called water vapor when it evaporates.

1. A thermometer is a tool used to measure temperature.

1. Surface area is the area of a liquid exposed to or touching the air.

1. When water vapor touches a cool surface, it condenses and becomes liquid water.

1. The water cycle is the sequence of condensation and evaporation of water on Earth, causing clouds and rain and other forms of precipitation.

The following are the main ideas from the three investigations that were part of this unit.

Properties of water – Investigation 1

Water is absorbed by some materials and beads up on others.

Surface tension makes water form a sphere (in the air) or dome (on a flat surface).

Soap added to water reduces its surface tension (flattens the dome).

Water flows down a slope.

Bigger domes of water move down a slope faster.

Water flows faster down a steep slope.

Cooling and Heating Water – Investigation 2

When the water in a thermometer is heated it expands, making the liquid column longer or move up the thermometer.

When the water in a thermometer is cooled, it contracts, making the liquid column shorter or move down in the thermometer.

Hot water is less dense than room-temperature water; it floats on room-temperature water.

Cold water is denser than room-temperature and hot water; it sinks in room-temperature water.

Water expands and turns solid when it freezes.

Ice is less dense than room-temperature water, therefore it floats. Cold water from the melting ice sinks.

Evaporation and Condensation – Investigation 3

Things dry when the water in or on them evaporates.

The cups placed in the warmest locations had the most evaporation.

The cups placed in the coolest locations had the least evaporation.

The greater the surface area, the faster the evaporation.

The smaller the surface area, the slower the evaporation.

When water vapor in the air touches a cool surface, it condenses into a liquid.

Evaporation puts water into the air. Condensation turns the vapor back into water, which falls to Earth as precipitation and keeps the global water cycle operating.