If Peter carries a 20 kg weight up a flight of stairs in 20 seconds and Mary carries the same 20kg weight up a flight of stairs in 30 seconds, who does the most work?

What makes the Pre-Archean time different from the others?

How does water vapor makes clouds

A balloon is at a height of 30 meters, and is rising at the constant rate of 5 m/sec. A bicyclist passes beneath it, traveling in a straight line at the constant speed of 10 m/sec.

Balance the following Equation: ___Zn + ___HCl - -> ___ZnCl2 + ___H2 50g of zinc are reacted with 50g of hydrogen chloride. Calculate the amount of excess reactant. A - 4.2g B - 5.1g C - 1.4g D - 2.3g

Which of the following is not a water soluble

In the process of covalent bonding, atoms share electrons. This means that * a) Electrons from each atom are attracted to the nucleus of both atoms b) Protons and neutrons attract c) Atoms lose electrons and become ions d) Atoms gain electrons and

Give the full atomic symbol for an atom that has 30 neutrons and an atomic number of 25

Maxwell, a russian scientist, created an early peridoc table of the elements. true or false

Can the nature of a reactant be altered to speed up reaction

What describes the basis of the band theory of metallic bonding