Physics ch. 11

How does a molecule differ from an atom? Give an example. 1. A molecule is composed of two or more atoms bonded together: H2O. 2. A molecule is made when two or more nuclei fuse together. 3. A molecule is a mixture of atoms: NaCl. 4. A molecule is made only when two or more of the same elements bond together: H2.

1. A molecule is composed of two or more atoms bonded together: H2O.

Which of these atoms has the largest number of neutrons in the nucleus? 1. Gold 2. Helium 3. Hydrogen 4. Carbon

1. Gold

What is a compound? Cite two examples. 1. Atoms pressed together without bonding: air and salt and sand 2. Atoms of different elements with bonds between them: NaCl and H2O 3. The same types of atoms bonded together: H2 and N2 4. Atoms of different elements with bonds between them: NaCl and H2

2. Atoms of different elements with bonds between them: NaCl and H2O

What is a mixture? Cite two examples. 1. The same types of atoms bonded together: H2 and N2 2. Atoms of different elements with bonds between them: NaCl and H2O 3. Atoms pressed together without bonding: air and salt and sand 4. Atoms pressed together without bonding: H2O and H2

3. Atoms pressed together without bonding: air and salt and sand

Which of the following are negatively charged? 1. Protons 2. Atomic nuclei 3. Electrons 4. Neutrons

3. Electrons

What is the evidence that dark matter exists? 1. Dark matter blocks distant light and can be seen as dark clouds in space. 2. When dark matter clouds collide, they emit light. 3. Gravitational forces within galaxies are too great to be accounted for with ordinary matter. 4. When dark matter falls into a black hole, it emits light.

3. Gravitational forces within galaxies are too great to be accounted for with ordinary matter.

How many shells are represented in the presently known periodic table? 1) 5 2) 1 3) 3 4) 7

4) 7

Where in the atom is most of its mass concentrated? What is this mass composed of? 1. In the nucleus as electrons 2. In the electron cloud 3. In a cloud of nucleons surrounding the nucleus 4. In the nucleus as protons and neutrons

4. In the nucleus as protons and neutrons

Distinguish between mass number and atomic mass. 1. Mass number is the number of protons; atomic mass is the total mass of an atom. 2. Mass number is the number of neutrons; atomic mass is the total mass of an atom. 3. Mass number is the number of electrons; atomic mass is the total mass of an atom. 4. Mass number is the number of nucleons; atomic mass is the total mass of an atom.

4. Mass number is the number of nucleons; atomic mass is the total mass of an atom.

The charge in the nucleus of an antimatter hydrogen atoms is __________. 1. negative 2. neutral, no charge 3. exotically different than positives and negatives 4. positive

1. negative

What did Robert Brown see under the microscope? 1. specks of dust moving around 2. atoms mixed with specks of dust moving around 3. atoms moving around

1. specks of dust moving around

Since atoms are mostly empty space, why don't we fall through a floor we stand on? 1. The atoms are always in motion, so they collide often. 2. Electrons in one atom repel the electrons in another. 3. Positively charged nuclei attract electrons from neighboring atoms, so they always collide. 4. The positively charged nuclei repel each other.

2. Electrons in one atom repel the electrons in another.

Compared with the energy it takes to separate oxygen and hydrogen from water, how much energy is released when they recombine? 1. No energy is released when they recombine. 2. The same amount of energy is released when they recombine. 3. More energy is released when they recombine. 4. Less energy is released when they recombine.

2. The same amount of energy is released when they recombine.

What occurs when a proton and an antiproton meet? 1. They electrically repel each other. 2. They annihilate each other. 3. They do not interact in any way. 4. They gravitationally repel each other.

2. They annihilate each other.

If you place a Styrofoam cup on the table and a bunch of BBs move around it randomly, what will happen to the cup, and why? 1. The cup will not move, because it is much larger than the BBs. 2. The cup will move steadily in one direction because of the uniform force exerted by the BBs pushing it in that direction. 3. The cup will move randomly in different directions because the BBs will exert unequal forces on the cup in different directions.

3. The cup will move randomly in different directions because the BBs will exert unequal forces on the cup in different directions.

How do matter and antimatter differ? 1. Matter emits light, whereas antimatter absorbs it. 2. Matter gravitationally attracts matter and repels antimatter. 3. When matter and antimatter meet, they annihilate in a flash of energy. 4. Antimatter has negative weight.

3. When matter and antimatter meet, they annihilate in a flash of energy.

Which of the following is an element? 1. A supernova 2. H2O 3. Carbon dioxide 4. Hydrogen

4. Hydrogen

Why did the particles jiggle around? 1. There was a constant external force that propelled the particles. 2. The particles were struck equally on all sides by atoms that were moving around. 3. The particles were struck by atoms, but unequally on different sides.

3. The particles were struck by atoms, but unequally on different sides.