Answer : The energy released by an electron in a mercury atom to produce a photon of this light must be, 
Explanation : Given,
Wavelength = 
conversion used : 
Formula used :

As, 
So, 
where,
= frequency
h = Planck's constant = 
= wavelength = 
c = speed of light = 
Now put all the given values in the above formula, we get:


Therefore, the energy released by an electron in a mercury atom to produce a photon of this light must be, 
Answer:
High temperature and low pressure
Explanation:
According to the kinetic molecular theory, gases are composed of small particles called molecules which are in constant motion.
At high temperature and low pressure, gas molecules possess high kinetic energy and move at high velocities hence intermolecular interaction is almost none existent and real gases approach the behavior of ideal gases.
Answer:
Here's what I get
Explanation:
The modern periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers.
I believe an atom. may be wrong, science is not my strong suit
Answer:

This is a double displacement reaction, C goes with Cl in the products side and O2 goes with H. All that is left is to balance the equation, making sure each side has equal amounts of atoms.