PS 100 final review part 3

The primary obstacle to controlled fusion reactions as a source of energy is

overcoming the electromagnetic repulsion of particles with like charges

How many hydrogen atoms are in three cis-platin molecules (3PtCl2N2H6)?

18

Uranium-238 alpha decays, emitting a helium-4 nucleus. What is the mass number of the product?

234

If the activity of a radioactive substance drops to 1/16 its initial value in 12 hours, its half life is

3 hours

Suppose the carbon and oxygen react according to the equation: O2 + 2C = 2CO. If you started with sixty oxygen molecules (60O2) and sixty carbon(60C), how many carbon monoxide molecules could you make?

60

How would the silicate units be connected for the mineral? (quartz)

A network of connected silicate molecules extending out in all directions

A metal can best be described as?

A network solid consisting of positively charged atoms in a sea of electrons

When you compare the ionization energies of K, Ca, and Ar which of the following is the least likely to give away an electron?

Ar

Which of the following is the most ordered? A. Nuclear potential energy B. Kinetic energy C. Chemical potential energy D. Thermal energy E. Electrical potential energy

B. Kinetic energy

Which ion would Ca most likely form?

Ca2+

Which of the following is NOT a characteristic of a metal or alloy? A. Electrically Conductive B. Thermally Conductive C. Malleable D. Brittle

D. Brittle

For the Butylene molecule C above, what forces would be the largest forces holding one of the molecules to another molecule? (What are the largest intermolecular forces?)

Dispersion forces

Metals have which of the following properties? A. Metals are good electrical conductors. B. Metals are poor conductors of heat. C. Metals are shiny. D. Metals are malleable. E. Metals are not very reactive with other elements. F. Metals easily form alloys. G. Metals form hard crystals with sharp faces. H. Metals are transparent.

Metals are good electrical conductors. Metals are shiny. Metals are malleable. Metals easily form alloys.

Which of the following tends to have the highest melting and boiling points?

Network matter

The modern definition of an element is a substance made up of atoms that all have the same number of

Protons

The gasoline engine of an automobile is considerably less than 100% efficient. This means that not all of the energy in the gasoline is turned into kinetic energy of the car. What best explains why?

Some of the chemical potential energy in the gasoline must become ambient thermal energy if the rest is to supply the kinetic energy of the automobile. This means some energy must be wasted.

Sugar is a covalent molecule that is solid at room temperature and dissolves easily in water. What does this information tell us about the molecule?

Sugar molecules are polar

The plot below is a graph of average nucleon mass versus atomic mass for nuclei.

The individual proton's and neutron's mass is smallest for atoms with a mass of about 50, and larger, for atoms with very small or very big mass.

A refrigerator is normally run with its door closed. What would happen if the refrigerator were placed in the middle of a closed room with its door open and turned on?

The room would heat up because all of the energy absorbed by the refrigerator, both thermal and electrical potential, is released back into the room as thermal energy.

Use the Periodic Table to decide if S is a metal or a nonmetal. Do the same for O. If these two form a compound, which of the following characteristics will it show at room temperature?

Transparent gas

Salts have which of the following properties? A. Conduct electricity B. Transparent C. Ionic bonds D. Combination of metal and nonmetal atoms E. Malleable

Transparent. Ionic bonds. Combination of metal and nonmetal atoms.

How do semiconductors change with increasing temperatures?

When you heat them up, semiconductors act more like metals.