4. True or false: The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency
A. True
B. False

Litmus paper is made from water-soluble dyes which are extracted from lichens. this paper is used as an acid-base indicator. which of these common household substances would turn blue litmus paper red? a) bleach b) lye c) soap d) vinegar

The first element on the periodic table of elements is carbon. a. true b. false

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line