Atoms

Biology Worksheet 2 KEY Student: ______________________

1. The hydrogen and oxygen atoms of water different molecules held together by hydrogen bonds.

2. How many covalent bonds can an atom of hydrogen have? one

3. How many electrons are shared in a single covalent bond? Two, one contributed by each atom

4. How many covalent bonds can an atom of hydrogen have? one

5. How many single covalent bonds can an atom of carbon have? four

6. True/False Carbon fill its outer shell by bonding to both another carbon atom and hydrogen atoms simultaneously.

7. Draw a molecule of diatomic oxygen below no need to draw the protons and neutrons in the nucleus:

8. Name the molecule to the right. How many electrons does each carbon share with hydrogen atoms? Six (two with each hydrogen) with another carbon atom? two

9. How do you know that this is an organic molecule? It has a carbon skeleton

10. What other term can we use to classify this type of molecule, based on its composition? hydrocarbon

11. Is this molecule polar or non-polar? nonpolar

12. If polar, what makes it polar? If non-polar, why is it nonpolar? I am deleting this question.

13. Name the second molecule to the right.

Carbon dioxide

14. How many electrons does the carbon share with each oxygen atom? four

15. Name the third molecule to the right and below. water

16. Why is this molecule polar? Because the hydrogen and oxygen atoms have opposing electrical charges and they are not arranged in a linear fashion thereby creating a polar molecule.

17. Draw the partial charges where they belong using the appropriate Greek letter.

18. In a water drop, the individual water molecules are attracted to one another. What part of the water molecules do the hydrogen atoms interact with? The oxygen atoms.

19. What are the attractive forces between the water molecules called? Hydrogen bonds

20. List three consequences of the cohesion of water...