A 337 nm nitrogen laser puts out 4.00 W of power with a beam 4.50 nm in diameter. The beam is pointed directly at a pinhole which has a diameter of 2.20 nm. How many photons of light will travel through the pinhole per second?

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

Margaret wants to make an orange flavored drink by stirring powdered drink mix into a glass of water. she doesn't like drinks that have small clumps of powdered solid in them, so she wants the drink to be a perfect solution. what factors should margaret not consider when deciding how much powder to add to her glass of water?

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next