Chemistry deals with the study of elements-- their properties, chemical reactions and their compounds. This science includes the study of how these elements or compounds are formed. The history of chemistry is divided to 4 periods.
Black Magic, Alchemy, Traditional Chemistry and Modern Chemistry comprised these periods.
How did the early chemists determine which of the substances are elements? Long time ago, chemists knew which substances could not be broken down and that mixtures are broken down through chemical means. Through the said process, they were able to identify which are elements from the substances they have tested.
Answer:
v = 2,99913 10⁸ m / s
Explanation:
The velocity of propagation of a wave is
v = λ f
in the case of an electromagnetic wave in a vacuum the speed that speed of light
v = c
When the wave reaches a material medium, it is transmitted through a resonant type process, whereby the molecules of the medium vibrate at the same frequency as the wave, as the speed of the wave decreases the only way that they remain the relationship is that the donut length changes in the material medium
λ = λ₀ / n
where n is the index of refraction of the material medium.
Therefore the expression is
v = 
Let's look for the frequency of blue light in a vacuum
f =
f = 
f = 6.667 10¹⁴ Hz
the refractive index of air is tabulated
n = 1,00029
let's calculate
v = 
450 10-9 / 1,00029 6,667 1014
v = 2,99913 10⁸ m / s
we can see that the decrease in speed is very small
Your answer should be B. Irregular
Sensible heat involves change in temperature of a substance. As the name suggests, it is the heat one can feel or sensed. When a system exchange sensible heat, its volume, pressure and state do not change. The sensible heat can be measured with the help of thermometer. The other type of heat is latent heat which involves change in state of the substance.
Answer:
Newton's Universal Law of Gravitation: 'a simple equation, but devastatingly effective'. ... The equation says that the force (F) between two objects is proportional to the product of their masses (m1 and m2), divided by the square of the distance between them.
Explanation:
