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.
Answer:
The Electron found by J.J Thompson
Explanation:
Hope this helps:)
Answer: People that are usually nearsighted have lots of difficulty reading road signs from far distance, also have difficulty with seeing distant objects clearly, and this is obviously something dangerous for a person who has trouble with seeing from far. And the weird thing is, they might have that difficulty but in the other hand, they are able to see very well from close-up tasks such as reading a book or seeing the computer screen clearly. This disability is called "myopia". In addition, people who are nearsighted also have difficulty seeing objects from far distance very blurry. Farsightedness is the result of the visual image being focused behind the retina rather than directly on it. It may be caused by the eyeball being too small or the focusing power being too weak.
I hope this helps answer your question! If you have options for this question, let me know k :) (Ask for help too)
The half life of a radio-isotope is the amount of time required for half of the isotope to decay into a new element or sister isotope. One half life results in a 50% loss of radioisotope, and two half lives results in a 75% loss. For three-fourths of the nuclei to decay, two half-lives must pass.
Answer:
16
Explanation:
Because the sum of all electron in that compound should be 41 and as it has one electron extra ,total no. of electrons are 42 .
So if we add 26 +16 we get 42
Hence it's correct answer
