Around 350 BC, the great Aristotle declared that the Earth was a sphere (based on observations he made about which constellations you could see in the sky as you travelled further and further away from the equator) and during the next hundred years or so, Aristarchus and Eratosthenes actually measured the size of the Earth!
Answer:
I don't think so for now, there hasn't been much research done with the vaccine and children so we really don't know how children's bodies will react to it. Once more studies are done with the vaccine and children and is proven safe then yes, kids should use it in order to attend public school.
Answer:
B
Explanation:
Assuming the units are all supposed to be the same
A cube shaped cell with a 1 um³ volume would have a dimensions of 1 x 1 x 1 (because volume = length x width x height and 1 x 1 x 1 =1)
If we double the dimensions, we have a cube with the dimensions 2 x 2 x 2.
The surface area of each face of the cube is the length x width, so 2 x 2. This means the surface area of each face of the cube is 4 um².
There are 6 faces of a cube, so the total surface area is 6 x 4 um² = 24 um².
The molarity of Barium Hydroxide is 0.289 M.
<u>Explanation:</u>
We have to write the balanced equation as,
Ba(OH)₂ + 2 HNO₃ → Ba(NO₃)₂ + 2 H₂O
We need 2 moles of nitric acid to react with a mole of Barium hydroxide, so we can write the law of volumetric analysis as,
V1M1 = 2 V2M2
Here V1 and M1 are the volume and molarity of nitric acid
V2 and M2 are the volume and molarity of Barium hydroxide.
So the molarity of Ba(OH)₂, can be found as,

= 0.289 M
The chemical formula for glucose is C6H12O6! If you have a specific question, feel free to ask :)