Answer:
6.25%
Explanation:
Given data:
Half life of lutetium-117 = 6.75 days
Percentage remaining after 27 days = ?
Solution;
Number of half lives = Time elapsed / half life
Number of half lives = 27 days / 6.75 days
Number of half lives = 4
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At 3rd half life = 25%/2 = 12.5%
At 4th half life = 12.5%/2 = 6.25%
Answer:
d
Explanation:
A greenhouse gas (sometimes abbreviated GHG) is a gas that absorbs and emits radiant energy within the thermal infrared range. Greenhouse gases cause the greenhouse effect on planets. The primary greenhouse gases in Earth's atmosphere are water vapor (H. 2O), carbon dioxide (CO. 2), methane (CH.
Answer:
a
Explanation:
it would be the most reasonable
True. Each contour line on a topographic map represent a certain elevation; the closer they are, the steeper the surface is. All points on a contour line are the same elevation.
Answer: Multiple covalent bonds may occur in atoms that contain carbon,nitrogen, or <u><em>oxygen</em></u>.