These answers provide an explanation for each question, highlighting the key concepts and relevant information for each choice. Remember, choosing the correct option requires careful consideration of the scientific principles and context presented in each scenario.
1. What characteristics are shared by all alkali metals and alkaline earth metals?
a. They conduct electricity very well: Both groups have readily available valence electrons in their outer shells, making them excellent conductors.
2. Carbon has an atomic number of 6. What can you conclude about carbon from this fact?
a. It has six protons: Atomic number represents the number of protons in an element's nucleus, so carbon has six protons.
3. Noble gases are sometimes called "inert gases." What can you infer about the meaning of the word "inert" in chemistry?
b. It refers to substances that do not react with other substances: Noble gases have stable electron configurations, making them unreactive ("inert") towards most elements.
4. What do the orange and yellow spheres represent in this model of an atomic nucleus?
b. Protons and neutrons: These are the fundamental building blocks of the nucleus, with orange representing protons and yellow representing neutrons.
5. What do the elements highlighted in red have in common?
d. The same number of electron shells: Elements in the same group share similar electron configurations, resulting in the same number of electron shells.
6. Which of the following is a true statement?
a. Periods form horizontal rows; groups form vertical columns: This is the standard representation of the periodic table, with periods running horizontally and groups vertically.
7. What is true of all atoms?
d. They contain at least one proton: The proton is the fundamental unit of positive charge in an atom, making its presence necessary for any atom to exist.
8. What is one key physical difference between transition metals and poor metals?
b. Hardness: Transition metals are known for their hardness and malleability, while poor metals tend to be brittle and soft.
9. If you wanted to find a sample of fermium, which has an atomic number of 100, where would you look?
c. In outer space: Fermium is a synthetic element, not found naturally on Earth. It can be produced in particle accelerators or nuclear reactors.
10. To become positively charged, an atom must:
d. Lose an electron: Losing an electron disrupts the balance of protons and electrons, making the atom positively charged (cation).