Semester One Review

Semester One Review

Let's review together!

Unit 1: Intro to physical science

Scientists use models to explain and predict the behavior of scientific ideas. For example, a wave pool might simulate a wave, or candies might be used to represent an atom.

Scientific Method

In an experiment, a scientist creates a hypothesis. Independent variables are changed by the scientist to obtain results that are shown by measuring the dependent variables.

Experiments must be run several times to make sure results are repetitive and consistent.

Multiple Choice

A scientist waters a plant 1 oz on day one, 2 oz on day two, and 3 oz on day three. She measures the height of the plant each day. Which is the independent variable?

• plant height

• how much water is given

• the color of the plant

• how many flowers bloom

Multiple Choice

Scientists must use repetition when completing experiments, what does repetition mean?

• to dance

• to change many variables

• to duplicate and repeat

Unit 2: Matter

Atoms make up all matter. They are made up of subatomic particles called:

Protons (positive charge)

Electrons (negative charge)

Neutrons (neutral charge)

Multiple Select

What are subatomic particles? (select all answers)

• Molecules

• Protons

• Neutrons

• Electrons

Multiple Choice

Which subatomic particle has a negative charge?

• Protons

• Neutrons

• Electrons

Periodic Table

When reading a periodic table, the atomic number tells us how many protons there are, and the mass number is the number of protons plus neutrons.

Atoms combine and bond to create molecules.

EX: hydrogen + oxygen = water

Multiple Select

The mass number tells us the combined number of what two subatomic particles? (select two answers)

• protons

• neutrons

• electrons

• atoms

Unit 3: Chemistry

The law of conservation of mass states that in a closed system, mass cannot be created or destroyed. In other words, what goes into an equation must equal what comes out.

REACTANTS react to produce PRODUCTS

Multiple Choice

2Mg + O ----> Mg + 3O

Which is the reactant?

• 2Mg +O

• Mg +3O

• What in the world?

Multiple Choice

BONUS:

Is the equation balanced?

2Mg + O ----> Mg + 3O

• Yes

• NO WAY!

Pure substances are homogenous, while layered substances are heterogenous.

Multiple Choice

Is chex mix with pretzels, cheetos, and peanuts heterogenous or homogenous

• Heterogenous

• Homogenous

• Neither

Chemical vs. Physical Changes

Chemical changes result in a changed substance, while physical changes result in the same substance but possibly may alter how the substance looks.

Multiple Select

Select all the examples of physical changes...

• sliced apple

• burning log

• melted ice

• shredded paper

Multiple Choice

Which change results in a new substance?

• physical change

• chemical change

Unit 4: Motion and Newton's Laws

Speed, distance, and time are all related and used to calculate motion.

Multiple Choice

A cheetah runs 50 mph for 2 hours - how far does he travel?

• 100 miles

• 200 miles

• 50 miles

• 1000 miles

Balanced and Unbalanced Forces

Balanced forces apply the same amount of force on an object from opposite directions, unbalanced forces are unequal.

Multiple Choice

If Chastyn pushes a box with 30 N force west and Lila pushes east with 25 N force, which direction will the box travel?

• west with 5 N force

• east with 5 N force

• west with 10 N force

• east with 15 N force

Unit 5: Force & Momentum

Objects with greater mass travel with more momentum and thus require more force to change velocity.

Forces can be contact forces that touch the object, or non-contact. There are several different types of forces: buoyant, electric, applied, normal, gravitational, magnetic, spring, and more!

How to pass your science class...

• Click "Grades" and complete any missing assignments. Redo any low grades.

• Go to Unit 5 and open the end of semester review. Study it!

• When you're ready take the End of Semester Celebration of Knowledge!

• If you do well and have a 60% or better in the class, YOU'RE DONE!

• If you don't do well, go back and study. Try again! Save an attempt for class on Monday if you need more help.