Answer:
Three half lives.
Explanation:
Given data:
Number of half lives passed = ?
Amount of parent isotope left = 12.5%
Solution:
At time zero = 100%
At 1st half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At third half life = 25%/2 = 12.5%
It means three half lives would passed.
Answer:
2.1 mol
Explanation:
68.1g / 34.1 g/mol = 2.1mol
Answer:
simple microscope has only one lens
:)
Answer:
A. Polar regions receive less solar energy and heat per unit area than tropical regions.
Explanation:
The sun is lower in the sky the farther away from the equator you go (at higher latitudes), so the solar energy is less direct. Climate in areas with less direct solar input tends to be generally cooler.