Answer:
Niels Bohr, refined the model of an atom by proposing a quantized shell structure atomic model in order to describe how the electrons are able to maintain stable orbits around the nucleus
Based on the predictions of classical mechanics the electron motion of the Rutherford model was unstable as the electrons where expected to have lost some energy during motion and thus having to come rest in the nucleus
According to the modification by Neils Bohr in 1913, electrons move in shells or orbits of fixed energy and emission of electromagnetic radiation takes place only when electrons changes the orbit in which they move
Explanation:
Types of Bonds can be predicted by calculating the
difference in electronegativity.
If, Electronegativity difference is,
Less
than 0.4 then it is Non Polar Covalent Bond
Between 0.4 and 1.7 then it is Polar Covalent Bond
Greater than 1.7 then it is Ionic
For Br₂;
E.N of Bromine = 2.96
E.N of Bromine = 2.96
________
E.N Difference
0.00 (Non Polar Covalent Bond)
For MgS;
E.N of Sulfur = 2.58
E.N of Magnesium = 1.31
________
E.N Difference 1.27 (Ionic Bond)
For SO₂;
E.N of Oxygen = 3.44
E.N of Sulfur = 2.58
________
E.N Difference 0.86 (Polar Covalent Bond)
For KF;
E.N of Fluorine = 3.98
E.N of Potassium = 0.82
________
E.N Difference 3.16 (Ionic Bond)
Result: The Bonds in Br₂ and SO₂ are Covalent in Nature.
Answer:
2.0x10¹⁷ Hz is the frequency of the X-ray
Explanation:
We can find the frequency of a wave of energy from the wavelenght and its speed using the formula:
v = λƒ
<em>Where v is speed (For electromagnetic radiation = 3.0x10⁸m/s)</em>
<em>λ is the wavelength in meters = 1.5x10⁻⁹m</em>
<em>And f is the frequency in s⁻¹ = Hz</em>
<em />
Replacing:
3.0x10⁸m/s = 1.5x10⁻⁹m*ƒ
3.0x10⁸m/s / 1.5x10⁻⁹m = f
f =
<h3>2.0x10¹⁷ Hz is the frequency of the X-ray</h3>
<em />
The number of neutrons in an atom is the number of particles present in its nucleus.
The atomic number is the number of protons whereas the mass number is the number of protons and number of neutrons together
This implies that the number of neutrons is the atom's mass number
Answer:
B. Particles of matter have spaces between them.
Explanation:
The particle nature model of matter is an model used to explain the properties and nature of matter. The statements of the particle nature model of matter are as follows :
1. Matter is made of small particles of atoms or molecules.
2. The particles of matter have space between them. The spaces between the particles are least in solids as they are closely packed together but are greatest in gases whose particles are far apart from each other.
3. The particles of matter are in constant motion at all times. Solids particles are not free to move due to strong molecular forces between the particles, but are constantly vibrating in their mean positions. Liquid particles free to move due to lesser molecular forces while gas molecules which have negligible intermolecular forces have the greatest ability to move.
4. The particles of matter are attracted to each other by intermolecular forces. These forces are greatest in solids and least in gases.
The correct option is B.