Counting on Nature 2008
Changing Patterns
3. Interpret Tables The upper
limit of the red birch (RB) rises
over time. What happens to the
mountain birch (MB) and its lower
limit?
2013
2018
2023
Semem
Segment
RM
YY
35
M
33
Y
Y
31
9 of 14

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called