Answer:
a one rotation of the planet on its axis
Explanation:
The two types of motion that planets undergo are;
1) rotation of the planet about its axis
2) revolution of the planet around the sun.
In every planet there are days as shown in the image attached to the question. However, the length of day in each planet is determined by the time required for the planet to complete one rotation on its axis.
It takes the earth 1 earth day (24 hours) to complete rotation on its axis.
The centers for disease control and prevention (CDC) develops recommendations for water fluoridation along with technical requirements for each major compound used.
<h3>What is meant by water fluoridation?</h3>
Almost all water contains some fluoride, but usually not enough to prevent tooth decay. Fluoride can also be added to drinking water supplies as a public health measure for reducing cavities. Water fluoridation is the process of adding fluoride to the water supply so the level reaches approximately 0.7 ppm or 0.7 milligrams of fluoride per liter of water, this is the optimal level for preventing tooth decay.
To learn more about water fluoridation, visit:
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Answer:
1.99grams
Explanation:
- First, we need to calculate the molar mass of the compound: Ca(HCO3)2
Ca = 40g/mol, H = 1g/mol, C = 12g/mol, O = 16g/mol
Hence, Ca(HCO3)2
= 40 + {1 + 12 + 16(3)}2
= 40 + {13 + 48}2
= 40 + {61}2
= 40 + 122
= 162g/mol
Molar mass of Ca(HCO3)2 = 162g/mol
- Next, we calculate the mass of oxygen in one mole of the compound, Ca(HCO3)2.
Oxygen = {16(3)}2
= 48 × 2
= 96g of Oxygen
- Next, we calculate the percentage composition of oxygen by mass by dividing the mass of oxygen in the compound by the molar mass of the compound i.e.
% composition of O = 96/162 × 100
= 0.5926 × 100
= 59.26%.
- The number of moles of the compound, Ca(HCO3)2, must be converted to mass by using the formula; mole = mass/molar mass
0.0207 = mass/162
Mass = 162 × 0.0207
Mass = 3.353grams
However, in every gram of Ca(HCO3)2, there is 0.5926 g of oxygen
Hence, in 3.353grams of Ca(HCO3)2, there will be;
0.5926 × 3.353
= 1.986
= 1.99grams.
Therefore, there is 1.99grams of Oxygen in 0.0207 moles (3.353g) of Ca(HCO3)2.
Answer:
2 significant figures i.e. 2 and 7.
Explanation:
We need to find the number of significant figures in the given number i.e. 
.
It has 2 significant figures i.e. 2 and 7.
It means the power of 10 doesn't count in the significant figures.
Hence, there are 2 significant figures.
Hihi!
The answer would be 10046528.8! I got this answer by first taking 2.45 x 1013 which equals 2481.85, then I took which equals <span>4048. So then finally you take your two answer and multiply them! (248.85 x 4048) </span>
I hope I helped!
-LoliArual
