Answer:
bohr descirbed the atomic structure and found that electrons travel in separate orbits around the nucleus. jj thomson created the plum pudding model.
Answer :- In a light wave the property of wave which tells about the color of light is it's Wavelength .
Wavelength is the distance between one crest and one through , also it is the distance after which the wave repeat itself !
It's SI unit is meter !
It is scalar quantity !!
Different Wavelength of light have different color !!
• VIBGYOR
i.e, Violent , Indigo , Blue , Green , Yellow Orange, and Red along with their shades are the colors which we can see !!
• They almost range from 400nm to 700nm ( visible range of light )
Answer
b. 95%
Explanation
Given:
Mass of K₂O produced (actual yield) = 28.56 g
Mass of K that reacted = 25.00 g
Equation: 4K(s) + O₂(g) → 2K₂0(s)
What to find:
The percent yield of K₂O.
Step-by-step solution:
The first step is to calculate the theoretical yield of K₂O produced.
From the balanced equation, 4 mol K produced 2 mol K₂O
Molar mass of K₂O = 94.20 g/mol)
Molar mass of K = 39.10 g/mol)
This means 4 mol x 39.10 g/mol = 156.40 g K produced 2 mol x 94.20 g/mol = 188.40 g K₂O
So 25.00 g K will produce:
Actual yield of K₂O = 28.56 g
Theoretical yield of k₂O = 30.1151 g
The percent yield for the reaction can now be calculated using the formula below:
Therefore, the percent yield for the reaction is 95%.
Atoms must gain or lose electrons in order to become ions if they are to form ionic bonds.
Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
