1) Compounds:
a) Chemically combined.
b) Components change properties.
c) Fixed proportions.
2) Mixtures:
a) Physically combined.
b) Components retain properties.
c) Variable proportions.
3) Both:
a) Made of elements.
b) 2 or more components.
A compound is a pure substance because its molecule cannot be broken down into simpler particles by physical means. For example water (H₂O) is a chemical compound made of two elements (hydrogen and oxygen).
In chemical change new substances are formed, the atoms are rearranged and the reaction is followed by an energy change.
There are no chemical bonds between substances in the mixture.,For example, mixture is solution of water and alcohol.
When temperature changes it melts the ice over the lake.
- As we know the melting point of ice or water is 0°C or 273K
- So if the temperature arises up to 0°C or 273.16K then the ice starts melting .
Explanation:
(a)
The relation between frequency and wavelength is shown below as:
c is the speed of light having value
Given, Wavelength = 505 nm
Also, 1 m =
nm
So,
Wavelength =
m
Thus, Frequency is:
(b)
Also,
Where,
h is Plank's constant having value
c is the speed of light having value
So,


(c)
Electromagnetic spectrum is range of the frequencies and their respective wavelengths of the various type of the electromagnetic radiation.
In order of the increasing frequency and the photon energy and the decreasing wavelength the spectrum are:
Red , Orange, Yellow, Green, Blue, Indigo, Violet
Increasing wavelength is the opposite trend. Thus, The longest visible wavelength is red and the shortest is violet.
I think is true not sure but it might be