user: Q: What force holds planets in their orbits?   Read this paragraph and choose the correct option from the provided answers:  Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a string. The force pulling the planet is the pull of gravity between the planet and the Sun.   Choices:  - magnetism  - centrifuge  - Big Bang  - gravity   A:
gravity


Q: The process in which the nucleus divides is called what?   Read this paragraph and choose the correct option from the provided answers:  In eukaryotic cells, the nucleus divides before the cell itself divides. The process in which the nucleus divides is called mitosis. Before mitosis occurs, a cell’s DNA is replicated. This is necessary so that each daughter cell will have a complete copy of the genetic material from the parent cell. How is the replicated DNA sorted and separated so that each daughter cell gets a complete set of the genetic material? To understand how this happens, you need to know more chromosomes.   Choices:  - meiosis  - epistasis  - cytokinesis  - mitosis   A:
mitosis


Q: Q: What light-producing process occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light?   Read this paragraph and choose the correct option from the provided answers:  A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure below contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light.   Choices:  - candescence  - resistance  - luminescence  - fluorescence   A:
A: fluorescence


Question: Q: Changes of state of matter do not involve what type of reaction?   Read this paragraph and choose the correct option from the provided answers:  Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed.   Choices:  - gaseous reaction  - radiation  - mechanical reaction  - chemical reaction   A:
Answer: chemical reaction


*Question*
Q: What are changes in makeup and chemical properties of matter called?   Read this paragraph and choose the correct option from the provided answers:  Chemical changes are changes in the makeup and chemical properties of matter. An example of a chemical change is wood burning.   Choices:  - mineral changes  - carbonate changes  - radical changes  - chemical changes   A:
**Answer**
chemical changes


*Question*
Q: When an action and reaction occur, what is transferred from one object to the other, yet in combination it remains the same?   Read this paragraph and choose the correct option from the provided answers:  When an action and reaction occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum .   Choices:  - matter  - force  - energy  - momentum   A:
**Answer**


assistant: momentum