Q: Electrons are located at fixed distances from the nucleus, what are they called? A:

OPTIONS:
- Energy layers
- Positive levels
- energy concentrations
- energy levels

Answer: energy levels

Problem: OPTIONS:
- elastic
- seismic
- tidal
- electromagnetic
Q: Q: What kinds of waves are composed of various oscillating electric and magnetic fields? A:
Answer: electromagnetic

Problem:OPTIONS:
- becomes unstable
- increases
- decreases
- remains stable

Q: The rate of decay of carbon-14 does what over time? A:
****
A: remains stable

Q: Emissions of what gas into the atmosphere from fossil fuel burning have been rising for the past several decades? A:
OPTIONS:
- sulphur
- oxygen
- neon
- carbon dioxide
carbon dioxide

Q: Rounded grains indicate that the minerals eroded from what? A:
OPTIONS:
- iron
- fossils
- recent rock
- earlier rock

Answer: earlier rock

input with options: Q: What is always conserved in chemical reactions? A:
OPTIONS:
- energy
- bonds
- force
- mass
output:
mass