Barium fluoride (BaF2) - Also known as Barium(II) fluoride - because it's a combination of two different kinds of ions (binary = two).
Answer:
Generally, the first ionisation energy increases along a period. But there are some exceptions one which is not an exception
Answer:
Oxygen is the most contain in earth but you asked in a,b,c and d. So I'll choice A. aluminium.
Answer : The initial temperature of system 2 is, 
Explanation :
In this problem we assumed that the total energy of the combined systems remains constant.
The mass remains same.
where,
= heat capacity of system 1 = 19.9 J/mole.K
= heat capacity of system 2 = 28.2 J/mole.K
= final temperature of system =
= initial temperature of system 1 =
= initial temperature of system 2 = ?
Now put all the given values in the above formula, we get
Therefore, the initial temperature of system 2 is, 
Answer:
1. The dye that absorbs at 530 nm
Explanation:
With a larger HOMO-LUMO gap, there's also a higher absorption energy, so this means that the dye with the higher absortion energy has the larger HOMO-LUMO gap.
The relationship between energy and wavelenght can be expressed by the formula E = hc/λ, this means that the <em>lower</em> the wavelenght, the <em>higher</em> the energy is. So the dye that absorbs at a lower wavelenght has a larger HOMO-LUMO gap.