You measure a small block of gold (d=19.3g/cm3) to be 2.777 inches long, 2.434 inches wide, and 1.688 inches high. what is the mass of the gold block in kg? (2.54cm=1inch exactly)

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

What is the percentage of hydrogen in nitrogen trihydride

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom