<h3><u>Answer</u>;</h3>
Concave Lenses
<h3><u>Explanation</u>;</h3>
- A concave lens is thin in the middle and thick at the edges, such that it seems to cave inwards. It spreads light rays apart producing an image smaller than the actual object.
- <em><u>Images formed by a concave lens are virtual, upright, reduced in size and located on the same side of the lens as the object. Diverging lenses or concave lens always produce images that share these characteristics. The location of the object does not affect the characteristics of the image. </u></em>
Answer:
1.98x10⁻¹² kg
Explanation:
The <em>energy of a photon</em> is given by:
h is Planck's constant, 6.626x10⁻³⁴ J·s
c is the speed of light, 3x10⁸ m/s
and λ is the wavelenght, 671 nm (or 6.71x10⁻⁷m)
- E = 6.626x10⁻³⁴ J·s * 3x10⁸ m/s ÷ 6.71x10⁻⁷m = 2.96x10⁻¹⁹ J
Now we multiply that value by <em>Avogadro's number</em>, to <u>calculate the energy of 1 mol of such protons</u>:
- 1 mol = 6.023x10²³ photons
- 2.96x10⁻¹⁹ J * 6.023x10²³ = 1.78x10⁵ J
Finally we <u>calculate the mass equivalence</u> using the equation:
- m = 1.78x10⁵ J / (3x10⁸ m/s)² = 1.98x10⁻¹² kg
Answer:
The answer is B (sodium is more reactive)
Explanation:
