Matter and Atoms Worksheet

What is matter?

• Matter is anything that takes up space and has mass.

• Everything around you, like air, water, and your desk, is made of matter.

• Properties of Matter: a. Density – How much stuff is packed into a space (heavy/light for its size) b. Conducts Electricity – some materials let electricity pass through them (like metal), while others do not (like rubber). c. Hardness – Some soft (cotton), others hard (diamond). d. Color – Different substances have different colors. e. Texture – How something feels (smooth, rough, bumpy, etc.).

What are atoms?

• Atoms are the tiny building blocks of matter.

• Smallest form (basic unit) of matter (if it gets any smaller it is no longer that substance)

• Everything is made of atoms, just like Lego bricks build bigger objects.

Q3. If you cut a gold atom in half, does it act like gold?

• Yes, it still acts like gold.

• No, it no longer acts like gold.

Q4. Explain what an atom looks like.

• An atom looks like a small solar system with electrons moving around a nucleus.

• An atom is a flat disc with electrons on the surface.

• An atom is a solid sphere with no internal structure.

• An atom is a large cube with electrons at the corners.

Q5. What two particles are in the nucleus of an atom?

• Protons and electrons

• Neutrons and electrons

• Protons and neutrons

• Electrons and positrons

What are the weight and charge of the following particles?

• Proton → Weight: 1 amu, Charge: +1 (positive)

• Neutron → Weight: 1 amu, Charge: 0 (neutral)

• Electron → Weight: Almost 0, Charge: -1 (negative)

What is an electron cloud?

Where is electron located? Is there only one electron in an atom?

• Electrons: particles located outside the nucleus. Electrons do not ORBIT around the nucleus but rather move around the nucleus in a space called the electron cloud. They move very fast around the nucleus. Scientists can’t pinpoint exactly where an electron is at any moment, but they can predict the area where it’s most likely to be.

• Atoms can have many electrons. The number of electrons depends on the type of atom. For example, hydrogen has 1 electron, but oxygen has 8 electrons.

• Older models (like Bohr’s model) showed electrons orbiting in perfect circles, but the modern model shows them in fuzzy, unpredictable paths within the electron cloud.

• So instead of saying electrons orbit, it’s better to say:

• Electrons move around the nucleus in an electron cloud.

What is chemistry?

• The study of matter and how it changes.

• Long ago, people tried to turn metal into gold in a practice called alchemy.

• Even though they failed, they learned a lot about elements and reactions, which helped create modern chemistry!

• Chemistry helps us understand everything from cooking to explosions!

Why is phosphorus dangerous?