Answer:
Radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold the nucleus together due to an excess of either protons or neutrons.
Hope this helps!
Answer:
Because his first law states that an object with a net force of zero acting on it will remain at rest, if initially at rest, or it will maintain a constant velocity.
Answer: Physical change
Explanation: Quite simple as the starfish opening a clam would mean the starfish is physically changing the clams look.
Answer: high pressure because it's stable
Explanation:
Air mass is volume of air which has stable temperature, humidity and pressure horizontally. Over time, each air mass acquires properties of the region by residing over same part of a surface.
Areas of low pressure and high pressure occur where there is warm air and cold air respectively. An air mass usually forms over an area of high pressure. Warm air rises up and cold air takes its place. Warm air has low density and low pressure where as cold air has high density and pressure and therefore, sinks to the bottom. This is a stable condition. The movement of air mass is responsible for maintenance of temperature conditions on Earth.