What should be done to ensure that a cation has completely precipitated from solution? select all that apply.

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

Find the mass in grams of 1.37x1020 particles of h3po4

What are the first three quantum numbers for the electrons located in subshell 2s?