Answer:

Explanation:
We are asked to find how many moles are in 4.8 × 10²³ fluorine atoms. We convert atoms to moles using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of fluorine.
We will convert using dimensional analysis and set up a ratio using Avogadro's Number.

We are converting 4.8 × 10²³ fluorine atoms to moles, so we multiply the ratio by this number.

Flip the ratio so the units of atoms of fluorine cancel each other out.


Condense into 1 fraction.

Divide.

The original measurement of atoms has 2 significant figures, so our answer must have the same. For the number we found, that is the hundredths place. The 7 in the thousandths tells us to round the 9 in the hundredths place up to a 0. Then, we also have to round the 7 in the tenths place up to an 8.

4.8 × 10²³ fluorine atoms are equal to <u>0.80 moles of fluorine.</u>
genetics and reproduction is all about dna.
The early precambrian atmosphere consisted primarily of nitrogen and carbon dioxide with almost no oxygen.
<span>Today, the atmosphere contains about 20% oxygen, less carbon dioxide and similar amounts of nitrogen. </span>
<span>Photosynthetic green-leaf plants and trees are largely responsible for the change, converting carbon dioxide to oxygen.</span>
Answer:
Explanation:
It makes sense because Helium and Hydrogen only hold 1 and 2 subsequent protons/neutrons and electrons. When the Big Bang happened the entire universe was so hot that it was impossible for elements to form since it was impossible for electrons to stay bound to the atoms. After a few seconds the universe began to cool enough for electrons to bond to atoms and create different elements. Since Helium and Hydrogen have 1 and 2 electrons subsequently we can assume that they were the first elements to be created. Also they are the most abundant elements in the Universe which backs up this theory.