It's inertia. A rule that you see every day, for example a brick will stay in the same spot unless a force acts on it.
Answer:
The lenses with different focal length are four.
Explanation:
Given that,
Radius of curvature R₁= 4
Radius of curvature R₂ = 8
We know ,
Refractive index of glass = 1.6
When, R₁= 4, R₂ = 8
We need to calculate the focal length of the lens
Using formula of focal length

Put the value into the formula



When , R₁= -4, R₂ = 8
Put the value into the formula



When , R₁= 4, R₂ = -8
Put the value into the formula



When , R₁= -4, R₂ = -8
Put the value into the formula



Hence, The lenses with different focal length are four.
<em>Answer: </em>tellurium (Te)
<em>atomic number = 52 ,</em>
<em>Number of energy levels = 5;</em>
First energy level = 2
Second energy level = 8
Third energy level = 18
Fourth energy level = 18
Fifth energy level = 6
<em>In this electron configuration, 0uter most electrons are 6.</em>
Answer:
An element is a pure substance and is made of only one type of atom.
Explanation:
It cannot be broken down into a simpler substance.