What is the difference between the units rem and rad? x a) rem is a conventional unit, and rad is an si unitb) rem is an si unit, and rad is a conventional unitc) rem is used to measure biological risk, and rad is used to measure absorbed radiationd) rem is used to measure absorbed radiation, and rad is used to measure biological risk.

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

If the particles in a sample of matter have an orderly arrangement and move only in place, the sample is a

Which statement is true about hcl? (5 points) select one: a. it is a salt because it increases the concentration of metallic ions. b. it is a salt because it is formed by the reaction of an acid and a base. c. it is an acid because it increases the concentration of hydroxyl ions. d. it is an acid because it increases the concentration of hydronium ions.