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:
Speed, v = 5 m/s
Explanation:
The length of the football field, l = 100 m
the person takes 20 seconds to run its length
v=
t
d
v=
20 s
100 m
v=5 m/s
Answer:
Photosynthesis
Explanation:
Carbon cycle involves the exchange of components between the hydrosphere, biosphere and atmosphere. During carbon cycle, materials such as gases, minerals which are necessary for life are interchange. For example, animals pass out faeces on the soil which is rich in urea. Urea decomposes to provide nitrogen into the soil through bioactive bacterials. The nitrogen is used up by plants to grow. During photosynthesis, plants uses carbon dioxide and water to produce glucose and release oxygen for animals to use. It's like a purification system where one waste product from one organism is used by the other to survive.
Equation of photosynthesis
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
Explanation:
1 mol = 22.4 l
5.42 mol = 22.4 × 5.42 = 121.408
in two decimal place it is 121.41
Answer:
carbon with graphite as the allotrope