NSCI 100 NSCI100 Quiz 3 with Answers (UMUC)

NSCI 100 NSCI100 Quiz 3

1. If you have two molecules of TiO_2, how many oxygen atoms would you have?
2. If you eat metallic sodium or inhale chlorine gas, you stand a strong chance of dying. Let these two elements react with each other, however, and you can safely sprinkle the compound on your popcorn for better taste. What is going on?
3. Many of the macroscopic properties of a compound depend on ________.
4. Which of the following has the greatest number of nonbonding pairs of electrons?
5. How many valence electrons does gallium (Ga, atomic no. = 31) have?
6. How do the electron-dot structures of elements in the same group in the periodic table compare with one another?
7. Which of the following elements will most likely not form an ion at all?
8. If a neutral atom loses one electron, what is the electrical charge of the atom?
9. How many oxide ions (O^-2) are needed to balance the positive charge of a titanium ion (Ti^+4)?
10. Which of the following substances is pure?
11. If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many pingpong balls would you need to equal the mass of two golf balls?
12. What is the formula mass of sulfur dioxide, SO_2?
13. The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?
14. How many grams of water can be formed from the reaction between 10 grams of oxygen and 1 gram of hydrogen?
15. The nucleus of an atom is charged
16. If you strip electrons from an atom, the atom becomes a
17. The repeating trends that take place when examining the elements are called ________.
18. Which chemical family is composed almost entirely of man-made elements?
19. Which element would have chemical properties the most similar to chlorine (Cl)?
20. Which of the following would be considered applied research?
21. A TV screen looked at from a distance appears as a smooth continuous flow of images. Up close, however, we see this is an illusion. What really exists are a series of tiny dots (pixels). This is similar to a chemist's view of matter in that
22. Which of the following is an example of a chemical change?
23. Which of the following is an example of a physical change?
24. Is aging primarily an example of a physical or chemical change?
25. A skillet is lined with a thin layer of cooking oil followed by a layer of unpopped popcorn kernels. Upon heating the kernels all pop thereby escaping the skillet. Which of the following physical and/or chemical changes occurred?