Freezing (solid), Melting (liquid), Evaporation (gas) Study Presentation INCLUDING WATER STATE CHANGE GRAPHS
Lesson Vocabulary 1. Melting- solids gain heat and change into liquids 2. Freezing- liquids lose heat and change into solids 3. Evaporation- liquids gain heat and change into gases 4. Condensation- gases lose heat and change into liquids 5. Boiling- liquids gain heat and quickly change into gases
Changing State How does an ice cube turn into a puddle of water? -It melts MELTING is the process by which a solid changes to a liquid. To melt a solid, you must add (HEAT) energy to it.
How does a puddle of water change from a liquid to a gas? -It can evaporate. EVAPORATION is the process by which a liquid changes to a gas.
What is happening when a liquid changes into a solid? FREEZING is the change of state from a liquid to a solid. *The particles move slowly and get close together. It causes liquid to freeze.
Is this an example of melting, freezing, or evaporating? a) Melting b) Freezing c) Evaporating
Answers
In which state is the snow? a) Melting
In which state is the puddle? a) Freezing
In which state is the puddle on the road? d) Evaporating
In which state is the road? b) Freezing
Part 2 Factors that influence the rate of Evaporation
Factor 1 - Temperature The higher the temperature the faster the rate of evaporation. Heat is added.
Which puddle will evaporate faster? A B
Factor 2 - Wind The more wind or air circulation the faster the rate of evaporation.
Which puddle will evaporate faster? A B
Factor 3 Exposed Surface Area The larger the exposed surface area the faster the evaporation rate. 1 inch 3 inches The water will evaporate more quickly from the beaker on the right with the wider opening.
If each beaker contains 8 ounces of water, which beaker will evaporate the quickest?
Part 3 Factors that influence the rate of Melting or Freezing
Factor 1 - Temperature Remember the freezing/melting point of water is 0 C or 32 F. The higher the temperature the faster water will melt. Heat is removed.????? The lower the temperature the faster water will freeze. Heat is removed.
Factor 2 - Size and Shape If you have two equal masses of ice one in a solid block and the other in smaller pieces - the smaller pieces will melt faster.
Factor 2 - Size and Shape (cont.) Just like with evaporation, the more surface area exposed to heat the faster water will melt. Likewise, the more surface area exposed to cold, the faster water will freeze.
In which cup will the ice melt quicker? A B
Factor 3 Changing the Composition During the cold and icy winter, you have probably experienced salt on sidewalks and roads. It is used to melt the ice and snow and keep it from refreezing. The freezing point of water becomes lower as more particles are added until the point where the salt stops dissolving.
By adding salt to icy roads, you change the freezing/melting from 0 C to point to -9 C.
Review Four Factors that influence the rate of Melting or Freezing Factor 1 Temperature (The hotter the air temperature the faster ice melts; the colder the air temperature faster water freezes.) Factor 2 - Size and Shape (Larger pieces of ice melt more slowly than an equal mass of smaller pieces.)
Factor 3 Changing the Composition (Mixing water with other compounds such as salt will influence the melting/freezing point.)
Practice Answer the following questions about factors that influence the rate at which different types of material freeze, melt, or evaporate.
Falling temperatures can affect the water cycle by. a) creating larger raindrops b) changing precipitation from rain to snow c) creating smaller raindrops d) changing the path of water runoff
How does adding salt to water affect the temperature? a) The melting point increases to a higher temperature. b) The freezing point increases to a higher temperature. c) Salt does not affect the temperature of water. d) The freezing point decreases to a lower temperature.
You are going camping for three days. You need to buy ice that will keep your ice chest cool for the entire 3 day trip. Which would be the best ice to buy? a) one large block of ice b) many small cubes c) crushed ice d) brightly colored cubes
At which of the following ground temperatures will the puddle evaporate the fastest? a) 50 C b) 15 C c) 29 C d) 87 C
Your little sister forgot to turn off the water in the bathroom sink. The water overflowed and soaked the carpet. You want to dry the carpet out before your mother gets home. At which level should you turn on the fan? a) low b) high c) medium d) The carpet would dry out faster without a fan.
Students are investigating whether wind affects the rate at which the sponge will dry. Which experiment is best to use in answering their question? a) b) c) d)
Each of the following containers hold exactly10 ounces of water. From which container will water evaporate the fastest? a) b) c) d)
Which letter represents evaporation?
At which temperature will the icicles melt the quickest? a) 50 C b) 15 C c) 29 C d) 87 C
Water State Change Graphs This will be on your FME quiz Graphs show how water changes at different temperatures
What does the previous graph show us? 1 2 3 4 Energy Added Graph Which number location represents the location of melting?
Answer 1 Why location 1? Reason: Location 1 is just above the solid line. The temperature is above freezing (0 degress Celsius). This is when melting will begin.
What does the previous graph show us? 1 2 3 4 Energy Removed Which number represents the freezing point?
Answer 4 Why? This is when freezing begins. 0 degrees Celsius Energy is being removed