Chemistry in Biology Chapter 6 STUDY GUIDE

1. What is Chemistry?

Chemistry is the study of matter – its composition and properties.

2. Matter

Matter is anything that has mass and takes up space

3. What are Atoms?

Atoms are the building blocks of matter

4. How big are atoms?

Atoms are so small that billions of them can fit on the head of a pin.

5. Is there anything smaller than an atom?

Yes, atoms are made of sub- atomic particles.

6. Differentiate the sub- atomic particles by completing the following chart :

Name of Particle Location of Particle Electrical charge of the Particle ProtonInside the Nucleus Positive NeutronInside the Nucleus No electrical charge: Neutral ElectronOrbiting around the outside of the nucleus in an Electron Cloud Negative

7. Draw and label a picture of an atom:

8. What is an Element?

An element is a pure substance. It is made of only ONE kind of atom.

Every element has a unique name and symbol. The first letter in the symbol is capitalized and the second letter is in lower case.

9. What is the Periodic Table ?

A chart that contains all of the known elements. A

B The Periodic Table is arranged into rows called Periods. The atoms are arranged on these periods by increasing atomic number.

C The Period Table is also arranged into columns called groups where all the members of a particular group have similar bonding characteristics

9. Draw and label an individual frame from the periodic table.

10. Differentiate the following terms by completing this chart.

Atomic Structure or Term Definition ProtonPositive charged particle found inside the nucleus NeutronNeutral particle within the nucleus ElectronsNegative Particles found in an electron cloud surrounding the nucleus Atomic NumberThe number of protons found in the nucleus. Atomic MassThe sum of protons and neutrons found in the nucleus

11. How do you determine the number of ___?_____ within the atom?

The number of protons? Check the atomic number. Whatever the atomic number is, that is how many protons you have. The number of electrons? In a neutral atom, the number of electrons equals the number of protons. So, when you check the # of protons, you can assume the number of electrons is the same. The number of neutrons? Subtract the atomic number from the atomic mass.

12. What is an ISOTOPE?

Atoms of the same element that have varying amount of neutrons.

In the following slide, notice the increasing atomic mass numbers. This is due to extra neutrons found within the nucleus.

13. What are Radioactive Isotopes?

When an atom with an unstable nucleus falls apart, radiation is emitted that can be detected and used in many applications.

14. Explain the importance of Carbon-14?

Carbon 14 is a radioactive isotope that is found in all living things. A

B Scientist know the half life (the amount of time it takes for half of carbon-14 to decay) so they can calculate the age of an object by finding how much carbon- 14 remains in the sample.

Other radioactive isotopes have medical uses, such as in radiation therapy to treat cancers. C

15. What is a COMPOUND?

A substance formed when 2 or more elements combine. A

The smallest particle of a compound would be the MOLECULE. B

C Each compound has a chemical formula formed from the symbols of elements within the compound. H2OH2O

D Compounds are always formed from a specific combination of elements in a fixed ratio. H2OH2OH2OH2OH2OH2O

The compound formed has DIFFERENT properties than the elements it is made up of. E

Iron bonds with oxygen

The compound cannot be separated by physical means. It requires a chemical reaction to separate the elements in a compound. F

16. Examples of Compounds

Name of compound Chemical Formula Elements within the compound Table Salt NaCl One Sodium One Chlorine WaterH2OH2O Two Hydrogens One Oxygen SugarC 6 H 12 O 6 Six Carbon Twelve Hydrogen Six Oxygen

17. What is a Chemical Bond ?

The FORCE that holds the elements together within a molecule. A

The elements are held together by the electrons in the last electron levels of the element’s Electron Cloud B

C If the two elements SHARE ELECTRONS then a COVALENT BOND FORMS.

If one element loses electrons and the other gains that electron, then an IONIC BOND FORMS. D

18. Covalent Bonds

A Two or more substances share electrons. The shared electrons will orbit both nuclei

B Depending upon the particular elements involved, the atoms may share 1,2, or 3 electrons.

C A compound formed from a covalent bond is called a molecule.

19. Ionic Bonds.

A Formed from a metallic element and a non- metallic element.

B The metal gives away its valence (outer) electrons and the non-metal gains the lost electrons

C Once the metal gives away the valence electrons, it loses part of its negative charge and becomes positively charged

D The non-metal gained negative charge when it captured the lost electrons

E The resulting compound is called an IONIC COMPOUND Pops Note! An ionic compound is like a molecule. But! Ionic bonds do not form Molecules. They form Ionic compounds

20. What is an ION?

A An ion is a atom that has either lost electrons from its valence level, or has gained electrons within its valence level.

B Ex. Lithium will lose 2 electrons and now has a +2 charge

C Ex. Oxygen will gain 2 electrons and now has a -2 charge.

D A metal can lose 1,2, or 3 electrons

E A non- metal can gain 1,2, or 3 electrons.

21. What is the difference between a molecule and an ionic compound?

The compound formed by a covalent bond is called a MOLECULE. The compound formed from an ionic bond is called an IONIC COMPOUND

22. What are VAN DER WAALS FORCES?

A Van Der Waals Forces are the attractions between two molecules.

B Even covalent bonds will have slight unequalities within their electron clouds, this will cause the Van Der Waals forces to attract the two molecules to each other.

23. Explain Van Der Waals forces in water.

A These forces cause the water molecules to stick together forming droplets

B These forces causes Water Tension at the surface of a container of water.

C People use dish detergent and washing powder to break up the surface tension so that the water can clean the dishes or clothes.