D is the answee your welcome
<u>Answer:</u> The average atomic mass of lithium is 6.9241 u.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
....(1)
- <u>For
isotope:</u>
Mass of isotope = 6 u
Percentage abundance of isotope = 7.59 %
Fractional abundance of isotope = 0.0759
- <u>For
isotope:</u>
Mass of isotope = 7 u
Percentage abundance of isotope = 92.41%
Fractional abundance of isotope = 0.9241
Putting values in equation 1, we get:
![\text{Average atomic mass of Lithium}=[(6\times 0.0759)+(7\times 0.9241)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20Lithium%7D%3D%5B%286%5Ctimes%200.0759%29%2B%287%5Ctimes%200.9241%29%5D)
Hence, the average atomic mass of lithium is 6.9241 u.
A mixture is a system that is made up of two or more substances which are not combined chemically. A pure substance is a system that only has one substance. The following are classified as:
1.water : pure substance
<span>2.blood : mixture</span>
<span>3.the oceans : mixture</span>
<span>4.iron : pure substance
5.brass : mixture</span>
<span>6.uranium : pure substance</span>
<span>7.wine : mixture</span>
<span>8.leather : mixture</span>
<span>9.table salt (NaCl) : pure substance</span>
The reaction of hydrogen gas (H2) with oxygen gas (O2) is a COMBINATION or SYNTHESIS reaction, because multiple substances combine to form fewer substances. Here, the two gases form one substance, water (H2O):
2H2 + O2 -- > 2H2O
40.0mL(1 L/1000 mL) = 0.040 L
<span>then plug into the formula M = moles/liters </span>
<span>0.035 M = moles/ 0.040L </span>
<span>multipy both sides by 0.040L, and you get 0.0014 moles </span>
<span>so the answer is 1</span>
