Answer: a) 
b) 
Explanation: Visible light is a form of electromagnetic wave.
Wavelength is defined as the distance between two successive crests of a wave. It is represented as symbol 
.
Frequency is defined as the number of complete cycles happening per second. It is represented by the symbol 
.
Wavelength and Frequency follow inverse relation,
where, c = speed of light = 
Wavelength and frequency of a wave is usually expressed in a range.
a) 
b) 
Answer:
4.90 M
Explanation:
In case of titration , the following formula can be used -
M₁V₁ = M₂V₂
where ,
M₁ = concentration of acid ,
V₁ = volume of acid ,
M₂ = concentration of base,
V₂ = volume of base .
from , the question ,
M₁ = ? M
V₁ = 125.0 mL
M₂ = 4.56 M
V₂ = 134.1 mL
Using the above formula , the molarity of acid , can be calculated as ,
M₁V₁ = M₂V₂
Substituting the respective values ,
M₁ * 125.0 mL = 4.56 M * 134.1 mL
M₁ = 4.90 M
There is no chemical change
I think the correct answer would be negative change in enthalpy, low temperature and negative entropy. Freezing of water is an exothermic process which means heat is released to the surroundings so negative enthalpy. And this is seen in the change to a lower temperature. Entropy is negative which signifies that there is more order as water freezes.
Hydrogen is usually –1. This is INCORRECT. The oxidation number for H is +1.
Oxygen is usually –2. This is CORRECT.
A pure group 1 element is +1. This is INCORRECT. It does not follow. This will depend on the other elements and the overall charge.
A monatomic ion is 0. This is INCORRECT. Diatomic ion is 0.
