What happens in a flame test? O A. Electrons are ejected from atoms when a sample is burned in the
flame.
B. Impurities in a sample are burned off in the flame until a pure
sample remains.
O C. A sample is melted in a flame to determine how much energy was
absorbed
O D. Electrons are excited to higher energy levels and their emissions
are observed.

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

The rate constant for the reaction below is 6.2 x 10−5 mol l−1 s −1. if the initial concentration of a is 0.0500 m, what is its concentration after 115 s?

Of element x has 22 protons, how many electrons does it have