Packet 23

3. Dead plant and animal material that falls to the ground or ocean floor. Detritus includes fallen leaves, dead insects, and other organic matter that becomes part of the soil.
5. Something that causes disease or illness. A pathogenic bacterium is a type of germ that makes you sick.
6. Happening in a specific order, one after another. The steps in a recipe are sequential—you follow them in order.
8. To gradually break down or rot over time. A banana will decay and turn brown if you leave it out too long.
9. The distance a number is from zero on a number line, always shown as a positive number. The absolute value of –5 is 5, and the absolute value of 5 is also 5. (Written as |–5| = 5)
10. Based on reason or logic; making sense. A rational decision is one you make by thinking carefully about the facts. (In math, a rational number can be written as a fraction.)

1. Not based on reason or logic; not making sense. An irrational fear is one that doesn't have a logical reason. (In math, an irrational number cannot be written as a simple fraction, like π.)
2. The process of breaking down or rotting. When a dead leaf decomposes, it breaks apart and returns to the soil.
4. Made unclean or impure by mixing with something harmful or unwanted. Contaminated water has harmful substances in it that make it unsafe to drink.
7. Having two sides that are exactly the same shape and size. A butterfly's wings are symmetrical because the left wing matches the right wing.