<u>Answer:</u> The element having similar chemical properties that of calcium present in period 3 is magnesium.
<u>Explanation:</u>
In a periodic table, elements are arranged in 18 vertical columns known as groups and 7 horizontal rows known as periods.
Elements arranged in a group show similar chemical properties because of the presence of same number of valence electrons.
We are given:
Calcium is the 20th element of the periodic table having electronic configuration 
It has 2 valence electrons.
The element present in period 3 and have the same number of valence electron or in the same group is magnesium.
Hence, the element having similar chemical properties that of calcium present in period 3 is magnesium.
Answer:
Cosmology is a branch of astronomy that involves the origin and evolution of the universe, from the Big Bang to today and on into the future. According to NASA, the definition of cosmology is "the scientific study of the large scale properties of the universe as a whole."
Answer:
hydroxide and hydrogen
Explanation:
When a metal reacts with water, a metal hydroxide and hydrogen are formed. Sodium reacts vigorously with water.
Your answer is :
P = K * x where P is partial pressure K is Henry's constant and x is solubility
<span>775 torr = K L·torr/mol * 0.0.0347 mole / liter </span>
<span>K = 775 / 0.0347 = 22334 L·torr/mol </span>
<span>in the second solution we have </span>
<span>1670 = 22334 * x </span>
<span>x = 1670 / 22334 </span>
<span>= 0.075 moles CO2 per liter of water.
</span>
Hope this helps :)
If you need anymore help with questions then feel free to ask me :D
1) Multiply the correct answer by 1% => 7.80009 * 1/100 = 0.0780009
2) Calculate minimum and maximum values:
a) Maximum: 7.80009 + 0.0780009 = 7.8780909
b) Minimum: 7.80009 - 0.0780009 = 7.7220891
3) Valid range: [7.7220891, 7.8780909]
4) Conclusion: 7.80, 7.730 and 7.80703 are inside the range and are inside the tolerance, while 7.6363, 7.6 and 7.76 are not.
