WATER CYCLE 4th Grade a. Plan and carry out investigations to observe the flow of energy in water as it changes states from solid (ice) to liquid (water) to gas (water vapor) and changes from gas to liquid to solid. Sources: Ed. Galaxy, HSP textbook, GPS

Stan left a container of warm water on the table. The container held exactly 160 milliliters of water. The next day, he noticed that the container held 150 milliliters. What is the BEST explanation for what happened? A Some of the liquid water turned into gas. B A decrease in temperature caused the volume to change. C Some of the water formed condensation on the sides of the container. D An ice cube was added to the container increasing the amount of water.

(A) Some of the liquid water turned into gas. Over time, liquid water evaporates, or changes into water vapor, a gas. When this happens, the vapor molecules escape into the atmosphere, leaving behind less liquid water in the container.

The following shows the changes in the state of water. Day Change of State 1 Liquid to solid 2 Gas to liquid Which of these correctly describes the change in the temperature of the water on one of the days? A from 0°C to 50°C on Day 1 B from 50°C to 0°C on Day 1 C from 30°C to 50°C on Day 2 D from 90°C to 0°C on Day 2

(B) from 50°C to 0°C on Day 1. At 50°C, water is liquid; at 0°C, water freezes into solid ice. According to the table, on Day 1 the liquid water becomes solid. (A) is incorrect because it describes the opposite process: solid ice melting into liquid water. (C) is incorrect because water is liquid at both 30°C and 50°C; it does not become gas until it begins to boil at 100°C. (D) is incorrect because it describes liquid water freezing into solid ice; according to the table, however, on Day 2 gaseous water vapor condenses into liquid water.

A student places a large chunk of ice in a pan and heats it on a stove. Which of these shows the correct order of changes that take place when ice is heated? A solid to gas to liquid because heat is added B solid to liquid to gas because heat is added C liquid to solid to gas because heat is removed D gas to liquid to solid because heat is removed

The correct answer is choice (B) solid to liquid to gas because heat is added. Adding heat causes solid ice to melt into liquid water; adding further heat causes liquid water to evaporate into water vapor, a gas. Choice (A) is incorrect because solid ice becomes liquid water before it becomes gaseous water vapor. Choices (C) and (D) are incorrect because heat is added to ice, not removed from it.

water vapor

The gas form of water.

condensation

The process by which a GAS CHANGES to a liquid.

evaporation

The process by which a LIQUID CHANGES into a gas.

water cycle

The constant movement of water from Earth's surface to the atmosphere and back to Earth's surface.