Which has the greater mass1 Kg lead or 1 Kg feathers?

A helium atom has 2 protons and 2 neutrons. what is the mass number of this atom?

Before a chemist can combine a solution with other liquids in a labratory, the temperature of the solution must be between 39C and 52C. The chemist places the solution in a warmer that raises the temperature 6.5c per hour.

How did dmitri mendeleev organize the periodic table

Which measure of central tendency would you use to find the average high temperature for the week

Groups, or families, in the periodic table have what in common? a. physical properties b. chemical properties c. the same number of neutrons d. the same number of electrons

Which element has an ion that is smaller than an ion calcium? Potassium, strontium, cesium, magnesium

A peregrine falcon can travel 537,600 furlong/fortnight. A race car travels 212ft/s. A spider can jump with a maximum velocity of 9,000,000 cm/hr. Which travels the fastest?

how many energy levels (shells) does an atom of oxygen have? How do you know this by looking at the periodic table?

A student needs to use 0.575 moles of sodium chloride in an experiment. How many grams should he mass out?

Which of the following seperation methods is used to seperate plant pigments? Filtration, Chromatography, fractional distillation, simple distillation?