QUARTER 1 SCIENCE 7

Why do scientists use models in their investigation?

• To replace actual experiments

• To make experiments more colorful

• To impress the public with advanced technology

• To explain phenomena that are difficult to see or detect

What does the Particle Model of Matter state about the composition of matter?

• Matter is made of tiny particles, and each pure substance has its own kind of particles

• Matter is continuous and cannot be divided

• All matter is made of the same particles

• Particles are always visible

Which of the following is not a basic principle of the particle nature of matter?

• Particles of matter are stationary

• Matter is composed of discrete particles

• There are empty spaces between particles of matter

• There are forces that act between particles of matter

Which statement best explains why liquids can flow?

• Liquid particles occupy a unit volume

• Their particles are fixed in position

• Their particles slide past one another

• They have the strongest forces between particles

Why do gases have lower density compared to solids and liquids?

• Gas particles move slowly

• Gas particles have more mass

• Gas particles are much smaller

• Gas particles are far apart with large spaces between them

Which best explains why solids are the densest among the three states of matter?

• They have the most number of particles per unit volume

• Their particles vibrate in fixed positions

• They have the weakest attractive forces

• Their particles cannot move freely

If you place a sealed balloon in the freezer, what will happen to the gas particles inside it?

• The particles will disappear

• The particles will move faster and spread apart

• The particles will slow down and move closer together

• The particles will remain unchanged in their size, arrangement, and overall state.

What happens when water changes state from liquid into gas?

• Water particles move faster and farther away from each other

• Water particles turn into hydrogen and oxygen atoms

• Water particles form stronger forces

• Water particles lose motion energy

Which statement correctly compares oxygen gas and liquid water?

• Liquid water particles have more spacing between them

• Oxygen gas particles have greater spacing between them

• Oxygen gas particles are arranged in fixed positions

• Both have the same spacing

A student claims that sugar water is a pure substance because it looks uniform. Do you agree or disagree?

• Agree, because it has only one visible phase

• Agree, because it is made of water and sugar

• Disagree, because it has different colors

• Disagree, because it is a homogeneous mixture of two substances