In the periodic table of elements, what do all of the elements in row 2 have in common?

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

Compare and contrast refraction of light and sound will give brainliest

Which of the following is most likely true about water in chemical solutions?