Explanation:
Distinguish chemical substances from mixtures
Key Points
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.
A chemical substance is composed of one type of atom or molecule.
A mixture is composed of different types of atoms or molecules that are not chemically bonded.
A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.
A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.
Various separation techniques exist in order to separate matter, including include distillation, filtration, evaporation and chromatography. Matter can be in the same phase or in two different phases for this separation to take place.
Terms
substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.
elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.
mixtureSomething that consists of diverse, non-bonded elements or molecules.
The answer to both is D. Here's why:
For the first, whenever motion changes in a magnetic field, it causes electrons to move. Electricity, which is needed to power a lightbulb, is just a term for movement of these electrons. Electrons aren't created, they're always there in the wire. It's just that the permanent magnet gets them to move, which produces electricity.
For the second, it is very similar to the first. A magnet won't cause any electric current at rest, it always requires motion in order to produce an electric current. If you keep both of those in mind, it should help in the future. Hope this helps!
Answer:
E = 3.77×10⁻¹⁹ J
Explanation:
Given data:
Wavelength of absorption line = 527 nm (527×10⁻⁹m)
Energy of absorption line = ?
Solution:
Formula:
E = hc/λ
h = planck's constant = 6.63×10⁻³⁴ Js
c = speed of wave = 3×10⁸ m/s
by putting values,
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 527×10⁻⁹m
E = 19.89×10⁻²⁶ Jm /527×10⁻⁹m
E = 0.0377×10⁻¹⁷ J
E = 3.77×10⁻¹⁹ J
n=20 mol
(NH)4 SO4
Atomic masses :
N- 14
H- 1
S- 32
O- 16
Therefore M= 14×2 + 1×8 + 32 + 16×4
= 132
m= nM
= 20×132
= 2640g
