ASVAB General Science Practice Test 990314

Questions 5
Topics Element, Geologic Time Scale, Meteoroids, Minerals, Periods

Study Guide

Element

An element is matter than cannot be separated into different types of matter by ordinary chemical methods.

Geologic Time Scale

The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.

Meteoroids

Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.

Minerals

Small quantities of certain minerals like iron, calcium, magnesium, and salt are important for nutrition and health.

Periods

The rows of the Periodic Table are called periods and contain elements that have the same number of electron shells ordered from lower to higher atomic number.