Science Concepts and Principles

Use the kinetic molecular theory of matter to describe the movement of particles.

• All matter is made of tiny particles that are always moving, and they get warmer and go faster depending on how hot they get.

• Particles in matter are stationary and do not move unless acted upon by an external force.

• Matter is composed of large particles that move slowly and do not change speed with temperature.

• The movement of particles is random and does not depend on temperature.

What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm³? Would it float in water?

• 0.75 g/cm³, it will sink

• 0.85 g/cm³, it will float

• 1.0 g/cm³, it will float

• 1.25 g/cm³, it will sink

How would you prove conservation of mass in a reaction that produces gas?

• By measuring the total mass before and after the reaction in a sealed container and confirming it is the same.

• By measuring the volume of gas produced and assuming it equals the mass lost.

• By conducting the reaction in an open container and observing the gas escape.

• By weighing the reactants only and not considering the products.

How are temperature and heat related?

• Temperature measures the energy of an object.

• Heat is the measure of how fast particles are moving.

• Temperature measures how fast particles are moving, while heat is the energy that moves from warmer to cooler objects.

• Heat is the temperature of an object.

How do we define mass and volume?

• Mass is the amount of matter in an object, and volume is the weight of an object.

• Mass is how heavy something is, and volume is how much space it takes up.

• Mass is the density of an object, and volume is the temperature of an object.

• Mass is the size of an object, and volume is the shape of an object.

How would the buoyancy of an object change if it were placed in saltwater vs. fresh water?

• Salt water is less dense, so it gives less buoyant force.

• Salt water is denser, so it gives more buoyant force which makes objects float better in salt water.

• Fresh water is denser, so it gives more buoyant force than salt water.

• Buoyancy remains the same in both saltwater and fresh water.

Why is dissolving sugar in water a physical change and not chemical?

• The sugar turns into a new substance.

• The sugar stays sugar and can be separated again by drying up the water.

• The water changes its chemical composition.

• The sugar reacts with the water to form a new compound.

Why is it possible to be precise without being accurate?

• Because precision means getting the same result repeatedly, even if it's wrong.

• Because accuracy is not important in scientific measurements.

• Because precision and accuracy are the same thing.

• Because being accurate requires multiple tests to confirm results.

What is the difference between accuracy and precision?

• Accuracy measures how close the size is measured to its exact size. Precision is how often your measurements are right, even if they’re not correct.

• Accuracy refers to the consistency of measurements, while precision refers to the closeness of measurements to each other.

• Accuracy is the degree to which a measurement approximates the true value, while precision is the degree to which repeated measurements yield the same result.

• Accuracy and precision are interchangeable terms that both refer to the correctness of measurements.

How would matter be different if atoms had no electrons?

• Atoms would still be able to form chemical bonds.

• Nothing would be alive without electrons.

• Atoms would be larger without electrons.

• Matter would be composed entirely of protons and neutrons.