What are characteristics of absorption spectra? Check all that apply. Light is absorbed, which produces characteristic lines.
Light is emitted, which produces characteristic lines.
Lines are dark on a visible light background.
Lines are brightly colored on a black background.
Lines are produced by electrons being excited.
Lines are produced from electrons returning to a lower energy level.

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

What metric units would you use to measure the thickness of a key