Grade 2 | SCIENCE
WEEK 19 • STUDENT TEXTBOOK • DAYS 91–95
Read each lesson with a parent or teacher and study the worked example. Then answer the questions for that day in the Week 19 Practice Workbook.
Week 19 Student Textbook | Week 19 Practice Workbook | Week 19 Teacher Guide | Week 18 Student Textbook | Grade 2 index
Day 91: Where Is Water Found on Earth?
Most of Earth’s water is in the ocean, and ocean water is salty. Only a small part of Earth’s water is fresh water, the kind people, plants and many animals need to drink.
Fresh water is found in rivers, streams, lakes and ponds. Some fresh water is underground, in spaces in soil and rock; people pump it up from wells, and it bubbles out at springs. Much of Earth’s fresh water is frozen as ice.
Worked example: Is the water in a well fresh water or salt water?
- Wells bring up water from underground.
- Underground water used for drinking is fresh water.
Worked answer: Fresh water.
Day 92: Water as a Solid and as a Liquid
Water on Earth can be liquid or solid. Liquid water flows in rivers, sits in lakes and fills the ocean. Solid water is ice and snow.
In very cold places, ice stays frozen all year. A glacier is a huge, thick sheet of ice on land that moves very slowly. Antarctica is covered by a giant ice sheet. In Alabama, the weather is warm most of the year, so almost all of its water is liquid; snow and ice are rare and melt quickly.
Worked example: Is rain solid or liquid water?
- Rain falls as drops that splash and flow.
- Water that flows is liquid.
Worked answer: Liquid.
Day 93: Earth Changes: Slow and Fast
Some changes to Earth’s surface happen slowly. A river wears away its banks a little at a time, over many years. Other changes happen fast. After very heavy rain, soil and rock on a steep hill can slide down in minutes. That is a landslide.
A sinkhole has a slow part and a fast part. In much of Alabama there is a rock called limestone underground. Rainwater soaking down slowly dissolves the limestone over many years, leaving empty spaces. The ground on top can stay in place for a long time. Then, when the space gets too big, the ground can collapse suddenly, sometimes in hours.
Worked example: A river slowly wears away its bank over 50 years. Is this a slow or a fast change?
- The change takes many years.
- Changes that take many years are slow.
Worked answer: Slow.
Day 94: Hands-On: Sort Earth Changes with Evidence
Scientists use evidence from sources to decide whether a change is slow or fast. Look for time words: over millions of years, over many years and little by little mean slow; in one day, in minutes and suddenly mean fast.
Today you will read six event cards from science sources and sort them, writing the words that are your evidence.
Worked example: A card says sand dunes moved a few feet each year. Which words are the evidence, and is the change slow or fast?
- Find the time words: a few feet each year.
- Moving a little each year is slow.
Worked answer: Evidence: a few feet each year. Slow.
Day 95: Independent Check: Water on Earth and Earth Changes
Today you will answer on your own.
Use what you learned this week: where water is found, solid and liquid water, and slow and fast changes.
Worked example: Is the water in a river solid or liquid?
- River water flows.
- Water that flows is liquid.
Worked answer: Liquid.
Week 19 Student Textbook | Week 19 Practice Workbook | Week 19 Teacher Guide | Week 18 Student Textbook | Grade 2 index