ASVAB General Science Practice Test 960959

Questions 5
Topics Atomic Mass, Atomic Number, Curved Lenses, Decomposers, Species

Study Guide

Atomic Mass

The atomic mass of an element listed in the Periodic Table represents the average mass of a single atom of that element and is measured in atomic mass units (amu). This number is an average as some elements have isotopes with atoms that vary in their number of neturons and, therefore, differ in weight.

Atomic Number

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.

Curved Lenses

Unlike curved mirrors that operate on the principle of reflection, lenses utilize refraction. A convex lens is thicker in the middle than on the edges and converges light while a concave lens is thicker on the edges than in the middle and diffuses light. A common use for curved lenses is in eye glasses where a convex lens is used to correct farsightedness and a concave lens is used to correct nearsightedness.

Decomposers

Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.

Species

The narrowest classification of life, species, contains organisms that are so similar that they can only reproduce with others of the same species.