A solar eclipse that occurs when the moon's
- umbra does not reach Earth's surface is called
1. an umbral solar eclipse.
2. a total solar eclipse.
3. a penumbral solar eclipse.
4. a partial solar eclipse.
5. an annular solar eclipse.

Which of the following does not describe a physical property of iron? a iron is silvery-white or gray in color. b iron has a boiling point of about 3,000°c. c iron is a magnetic element . d iron and sulfur react to form iron sulfide.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

What changes the stability of the element