Science 7 First Quarterly Assessment

Why do scientists use models?

• They are exact representations of reality.
• They only exist in computer simulations.
• They are always simple and easy to understand.
• They can be used to test ideas and make predictions.

What can be a limitation of scientific model?

• They are never updated or improved.
• They are all based on real-world data.
• They are only used in physics, not other sciences.
• They cannot perfectly capture all the complexities of a system.

What resembles the Plum Pudding Model of the atom?

• A tiny, solid ball with negative charges stuck on the outside.
• A complex mathematical equation describing electron behavior.
• A miniature solar system with planets orbiting a central nucleus.
• A positively charged sphere with negatively charges scattered throughout.

Why is the Plum Pudding Model helpful for scientists?

• It shows how atoms are mostly empty space.
• It shows electrons have specific energy levels.
• It shows how atoms are indivisible particles.
• It shows the nucleus is the most massive part of the atom.

What is the characteristic of solid particles as seen in its particle model?

• Moving freely and spread far apart.
• Arranged in a specific pattern but with large gaps.
• Vibrating in place with minimal space between them.
• Flowing around each other and constantly changing positions.

What can you say about the particles of liquid in contrast with a solid?

• A predictable pattern of movement.
• Less movement and are more tightly packed.
• The same amount of movement and spacing.
• More freedom to move and more space between them.

What happens to the particles of a material being heated?

• Slightly compacted but can move
• Moves farther away from each other
• Gains more definite shape and compactness
• Nothing happens because heat is not absorbed

What can be seen in the physical model of the Bohr model of the atom?

• Presence of orbitals
• A cloud of electrons
• A nucleus at the center
• Nothing, just empty space

Which of the following CAN NOT be a scientific model for the atom?

• A song with lyrics full of subatomic particles and their charges.
• An image (picture, concept map, flowchart, etc.) that considers all laws of science
• A round Styrofoam colored with parts representing electrons and other subatomic particles.
• A computerized interactive game where you can put subatomic particles and guess the correct image for atom.

An unknown white substance is heated and produced white smoke and black solid. What do you think is this substance?

• a mixture
• an element
• a compound
• a diatomic molecule