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3 years ago

Element M has two isotopes,^104M and ^106M.

1 answer:

3 0

To calculate atomic mass, you have to take to weighted average of the isotopes' masses. What that means is M = RA*106 + (1 – RA)*104, where RA is relative abundance expressed in decimal form. If you simplify the right side of that equation, you get M = 2*RA + 104. Doing a little more algebra yields RA = (M –104)/2 = (104.4 – 104)/2 = 0.4 / 2 = 0.2, which is 20%. So the answer is B.

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Which comppund contains both ionic and covalent bonds

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Answer:

potassium contains both Ionic and covalent bonds

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2 years ago

From top to bottom in most groups of elements, atomic radii tend to A. decrease because the nuclear charge increases. B. decreas

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D. As more electrons are added to an element, the number of electron orbitals being filled increases

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3 years ago

Read 2 more answers

A pharmacist wishes to strengthen a mixture from 10%alcohol to 30% alcohol. How much pure alcohol should be added to 7 liters of

Tomtit [17]

Answer:

2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.

Explanation:

Suppose x is the number of litres added to the 10% mixture than the quantity of new mixture is given as below

$n_{old}=7$ litres
$n_{new}=7+x$ litres

Also the quantity of alcohol is given as

$q_{old}=10 \% \, of \, 7 \, litres =0.7$

$q_{added}=x$

$q_{new}= 30 \% \,of \,new\, quantity = 0.3(7+x)$

Now the equation is as

$q_{old}+q_{added}=q_{new}\\0.7+x=0.3(7+x)\\0.7+x=2.1+0.3x\\x-0.3x=2.1-0.7\\0.7x=1.4\\x=2 \, litres$

So 2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.

8 0

3 years ago

Elements ending in the electron configurations ns^1 are highly reactive metals . What family does these elements belong to ?

myrzilka [38]

Answer:

<h3>A . Alkali metals</h3>

Explanation:

The highlighted elements of the periodic table belong to the alkali metal element family. The alkali metals are recognized as a group and family of elements. These elements are metals. Sodium and potassium are examples of elements in this family.

hope this helps

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3 years ago

1. How many molecules are found in 13.7 moles of CuNO3? <br><br> Please explain step by step

Gennadij [26K]

Answer:

1 moles

Explanation:

The answer is 0.0011897028836018. We assume you are converting between moles CuNo3 and gram. You can view more details on each measurement unit: molecular weight of CuNo3 or grams The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles CuNo3, or 840.546 grams.

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3 years ago