| Questions | 5 |
| Topics | Atomic Number, Carbon Cycle, Cell Division, Chemical Change, Prefixes |
The Periodic Table of the Elements categorizes elements primarily by the number of protons in their nucleus (atomic number) and secondarily by the characteristics they exhibit.
The carbon cycle represents the ciruit of carbon through Earth's ecosystem. Carbon dioxide (CO2) in the atmosphere is absorbed by plants through photosynthesis. Plants then die and release carbon back into the atmosphere during decomposition or are eaten by animals who breathe (respiration) the carbon into the atmosphere they exhale and produce waste which also releases carbon as it decays.
Cell division is the process by which cells replicate genetic material in the nucleus. Cell division consists of several phases:
| Phase | Major Process |
|---|---|
| interphase | chromosomes replicate into chromatids and the cell grows |
| prophase | chromatids pair up |
| metaphase | paired chromatids move to opposite sides of the cell |
| anaphase | cell elongates and nucleus begins to separate |
| telophase | separation of nucleus is complete resulting in two new nuclei |
| cytokinesis | cytoplasm and cell membranes complete their separation resulting in two separate cells |
During a chemical reaction molecules and atoms (reactants) are rearranged into new combinations that result in new kinds of atoms or molecules (products).
A prefix is added to the base units of the metric system to indicate variations in size. Each prefix specifies a value relative to the base unit in a multiple of 10. Common prefixes are:
| Prefix | Symbol | Relative Value | Example |
|---|---|---|---|
| mega | M | 106 (1,000,000) | Mm |
| kilo | k | 103 (1,000) | km |
| base unit | N/A | 1 | m |
| centi | c | 10-2 (1/100) | cm |
| milli | m | 10-3 (1/1,000) | mm |