Which statement is true about alkali metals

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

Abird flies directly overhead from where you stand at an altitude of 300.0 m and at a speed horizontal to the ground of 20.0 m/s. the bird has a mass of 2.0 kg. the radius vector to the bird makes an angle \thetaθ with respect to the ground. the radius vector to the bird and its momentum vector lie in the xyxy-plane. what is the bird’s angular momentum about the point where you are standing?