Unit 2 Study Guide DUE THUSDAY, OCT. 2ND (GRADED)

What is the smallest unit of an element?

• Molecule

• Compound

• Atom

• Electron

Answer explanation

The smallest unit of an element is an atom. Atoms are the basic building blocks of matter, while molecules and compounds consist of two or more atoms bonded together. Electrons are subatomic particles within atoms.

Which particle is found in the nucleus and has a positive charge?

• Neutron

• Proton

• Electron

• Ion

Answer explanation

The proton is a positively charged particle found in the nucleus of an atom, while neutrons are neutral, electrons are negatively charged, and ions are charged atoms or molecules. Thus, the correct answer is proton.

Which particle has no electrical charge?

• Proton

• Electron

• Ion

• Neutron

Answer explanation

The neutron is the particle that has no electrical charge, unlike protons which are positively charged and electrons which are negatively charged. Ions are charged particles, so the correct answer is the neutron.

Which particle orbits the nucleus of an atom?

• Proton

• Neutron

• Electron

• Quark

Answer explanation

The electron is the particle that orbits the nucleus of an atom, while protons and neutrons are found within the nucleus. Quarks are the building blocks of protons and neutrons, not orbiting particles.

The nucleus contains most of the atom's...

• Volume

• Mass

• Negative charge

• Space

Answer explanation

The nucleus contains most of the atom's mass because it is made up of protons and neutrons, which are much heavier than electrons. The other options, such as volume and space, are not primarily associated with the nucleus.

In which state of matter are particles tightly packed and vibrating in place?

• Liquid

• Gas

• Plasma

• Solid

Answer explanation

In solids, particles are tightly packed together and can only vibrate in place, unlike liquids and gases where particles are more spread out and move freely. Therefore, the correct answer is solid.

Which state of matter takes the shape of its container but has a definite volume?

• Solid

• Liquid

• Gas

• All of the above

Answer explanation

A liquid takes the shape of its container while maintaining a definite volume. In contrast, solids have a definite shape and volume, and gases take both the shape and volume of their container.

Particles in a gas are best described as...

• Fixed and vibrating

• Sliding past each other

• Moving freely and far apart

• Tightly packed

Answer explanation

Particles in a gas are not fixed; they move freely and are far apart from each other, allowing them to fill the container they are in. This distinguishes gas particles from those in solids and liquids.

Tags

NGSS.MS-PS1-4

What happens to the motion of particles when a substance is heated?

• They slow down

• They stop moving

• They speed up

• They get smaller

Answer explanation

When a substance is heated, the energy increases, causing the particles to move faster. This results in the particles speeding up, which is why the correct answer is 'They speed up'.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The arrangement of particles in a liquid is...

• In a fixed, rigid structure

• Far apart with no attraction

• Close together but able to move

• Layered and organized

Answer explanation

In a liquid, particles are close together but not in a fixed position, allowing them to move freely. This characteristic differentiates liquids from solids, which have a rigid structure, and gases, where particles are far apart.