Rb- Rubidium (atomic number 37 ): Rubidium is a very soft, silvery-white metal in the alkali metal group. Cs-Cesium (atomic number 55);

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

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