Answer:
68,2%
Explanation:
Supposing the initial salt concentration of lake Parsons is the same of non-isolated lakes, 6,67L, and the change of salt concentration in isolated lake is just for water evaporation it is possible to write:
6,67gL⁻¹×X = 21gL⁻¹×Y
<em>-Where X is the initial water and Y is the water that remains in the isolated lake-</em>
Thus:
6,67X = 21Y
0,318 = Y/X
0,318 is the ratio of water that remains between total water. To obtain the ratio of evaporated water:
1-0,318 = 0,682
In percentage: <em>68,2%</em>
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I hope it helps!
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Answer: 11.0 g of calcium will react with 10.0 grams of water.
Explanation:
To calculate the moles, we use the equation:
moles of 
The balanced chemical equation is:
According to stoichiometry :
2 moles of require = 1 mole of 
Thus 0.55 moles of require=
of
Mass of 
Thus 11.0 g of calcium will react with 10.0 grams of water.
<span><em>Answer:</em>
A strontium-90 atom that has a lost two electrons has <u>38</u> protons, <u>52</u> neutrons, and <u>36</u> electrons.
<em>Explanation:
</em>Atomic number<em> of </em>Strontium (Sr) is 38.
<em>Atomic number = number of protons
</em>Hence, Strontium has 38 protons.
If the element is in neutral state,
number of protons = number of electrons.
Then, neutral Strontium atom should have 38 electrons.
But the question says Sr has lost 2 electrons. Hence, number of electrons should be 38 - 2 = 36.
Mass number = number of protons + number of neutrons.
The given mass number is 90. Hence, number of neutrons should be 90 - 38 = 52.</span>
