What is the total mass of Kr-42 remaining in a 20-mg sample after 48.8 hours?

(1) 2.5 mg

(2) 5.0 mg

(3) 10 mg

4) 20 mg

What pigments can you expect to find in the spinach? (Select all that apply.) a. Anthocyanins (blue) b. Carotenes (orange) c. Porphyrins (red or yellow) d. Pheophytin a & b (gray) e. Chlorophyll a & b (green or blue-green) f. Xanthophylls (yellow)

Does an apple that is falling from a tree have just PE, just KE, or both? Explain

It requires 2,500 joules to raise a certain amount of water (c = 4.186J/g°C) from 20.0°C to 65.0°C. What is the mass of the water that is being heated? a 80 g b 138 c 40 g d 158 g

The element silver has two naturally occurring isotopes, 107Ag and 109Ag. The atomic mass of 107Ag is 106.905. It makes up 51.82% of naturally occurring silver. The average atomic mass of silver is 107.868 amu.

Given a mass of 12 g and a volume of 3 ml, calculate the density

How does concentration affect our daily lives in science?

How many nitrogen atoms are in 2.79 mo. of NH3

What is the chemical formula for polysaccharide?

What is the empirical formula of a compound composed of 32.9g of potassium and 6.73 g of oxygen

Glucose is not made from which of the following