For Al, its atomic number is 13 and its mass number is 27. How many neutrons does it have?
A.13
B. 14
C. 26
D. 27
E.40

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

The ozone molecule o3 has a permanent dipole moment of 1.8×10−30 cm. although the molecule is very slightly bent-which is why it has a dipole moment-it can be modeled as a uniform rod of length 2.5×10−10 m with the dipole moment perpendicular to the axis of the rod. suppose an ozone molecule is in a 8000 n/c uniform electric field. in equilibrium, the dipole moment is aligned with the electric field. but if the molecule is rotated by a small angle and released, it will oscillate back and forth in simple harmonic motion. what is the frequency f of oscillation?

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?