The asnwer to your question is A
Answer:
6 month interval
Explanation:
The distance to a nearby star in theory is more simple than
one might think! First we must learn about the parallax effect. This is the mechanism our eyes use to perceive things at a distance! When we look at the star from the earth we see it at different angles throughout the earth's movement around the sun similar to how we see when we cover on eye at a time. Modern telescopes and technology can help calculate the angle of the star to the earth with just two measurements (attached photo!) Since we know the distance of the earth from the sun we can use a simple trigonometric function to calculate the distance to the star. The two measurements needed to calculate the angle of the star to the earth caused by parallax (in short angle θ) are shown in the second attached photo.
So using a simple trigonometric function we can solve for d which is the distance of the earth to the star:
In the first attached photo a picture where r is the distance to the star and the base of the triangle is the diameter of the earth.
In rutherford experiment he bombarded highly energetic alpha particles towards the gold foil
He observed that most of the alpha particles pass through the foil without any deviation while very few of the alpha particles are there which reflect back to its own path
while very less in number was there which were deflected from there path
so he concluded that the positive charge of atom is concentrated inside the nucleus and it is small space in tom and electrons are surrounded them
so correct answer would be
4. In an atom, most of the mass and the positive charge are located in a small core within the atom called the nucleus.
The city monitors the steady rise of CO from various sources annually. In the year "C: 2019"<span> (rounded off to the nearest integer) will the CO level exceed the permissible limit.
If this isn't the answer, let me know and i'll figure out what it is. But I believe this is it. :) </span>
ISOTOPES (C) are atoms with the same number of protons, but different numbers of neutrons.
:)