How many electrons would hydrogen required to fill up that first shell?

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

Which of the following are sources of revenue for media companies? a. direct sales to producers b. advertising and subscriptions c. online purchase d. capital investments

Categorize them by metal, nonmetal, in periodic tableductilenon-ductilemalleableoft en gain electrons easilygood conductorpoor conductorcan be liquidselements