PLEASE HELP! Which of the following is true about a calcium atom (Ca) and a gallium atom (Ga)?
A. A calcium atom is larger and has more electrons.
B. A calcium atom is smaller and has more electrons.
C. A calcium atom is smaller and has less electrons.
D. A calcium atom is larger and has less electrons.

Which describe reflection? check all that apply. light bounces off a boundary.

For a particular reaction, ? h = -144.6 kj and ? s = -301.2 j/k. calculate ? g for this reaction at 298 k.

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?