Q: Each new horizontal row of the periodic table corresponds to the beginning of a new period because a new principal energy level is being filled with what? A:

OPTIONS:
- protons
- photons
- neutrons
- electrons

Answer: electrons

Problem: OPTIONS:
- bacteria
- colds
- flus
- virus
Q: Q: Ebola is an example of a disease spread by what kind of infectious agent? A:
Answer: virus

Problem:OPTIONS:
- nitrous oxide
- carbon monoxide
- helium
- carbon dioxide

Q: Soda fizzes when what common gas comes out of solution? A:
****
A: carbon dioxide

Q: What is the cause of the "heartburn" that occurs when acidic digestive juices escape into the esophagus? A:
OPTIONS:
- toxic reflux
- acidic buildup
- acid pressure
- acid reflux
acid reflux

Q: On a hot, dry day, plants close their stomata to conserve what? A:
OPTIONS:
- sunlight
- air
- cold
- water

Answer: water

input with options: Q: The oxygen regions of the water molecules have what kind of charge? A:
OPTIONS:
- positive
- neutral
- certain
- negative
output:
negative