If element X has 99 protons, how many electrons does it have

What causes the centripetal accleeration of an electron in a hydrogen atom?

Sort the numbers based on the numbers of significant figures they have 0.0093 120.9 1,000 1.008 670 0.184 1.30 - One significant figure - two significant figures - three significant figures - four significant figures

Why would you add a buffer to a reaction if all of the solutions are already neutral (pH 7) ?

Which is the best example of potential energy A) holding a basketball in the air B) rolling a ball across a flat table C) flowing electric current through a wire D) turning on a flashlight in a dark room

What is ethyl propyl ether? Is it dissolvable in water and hexane?

Does the amount of heat absorbed as 1 kg of saturated liquid water boils at 100°C have to be equal to the amount of heat released as 1 kg of saturated water vapor condenses at 100°C?

F. Protection of the body from infectious organisms is accomplished by which of these tissues? a) bone; b) muscle; c) nerve; d) blood

A compound that is composed of molybdenum (Mo) and oxygen (O) was produced in a lab by heating molybdenum over a Bunsen burner. The following data was collected: Mass of crucible: 38.26 g Mass of crucible and molybdenum: 39.

Which of the following elements has electrons in the 3d sublevel?

Which procedure can be used to separate the sand salt and water from each other