1. Analyze Element A and Element B by describing how to test 3 physical or chemical properties of the elements. 2. Explain how those results could be used to determine if they are a metal or nonmetal.

3. Based on these tests, identify Element A and Element B as metal or nonmetal.

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

Which organism develops breathing organism develops breathing organs from pharyngeal arches? shark, spider, sea star, sea horse

Imagine if during the cathode ray experiment, the size of the particles of the ray was the same as the size of the atom forming the cathode. which other model or scientific observation would have also been supported? 1. this would support dalton's postulates that proposed the atoms are indivisible because no small particles are involved. 2. this would support bohr's prediction about electrons moving in orbits having specific energy. 3. this would support bohr's prediction about electrons being randomly scattered around the nucleus in the atom. 4. this would support dalton's postulates that proposed that atoms combine in fixed whole number ratios to form compounds.