How many moles are represented by 3.01x10^23 helium atoms a. 1 mole

b. 0.50 moles

c. 0.75 moles

d. 5 moles

Iknow #2 is d. i just need to know why

What woukd most likely be the transmittance at a 0.70 m solution of solute a? a) 7.6%b) 1.1%c)4.0%d)4.6%

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.