Percent composition by mass is calculated (mass of element within compound)/(mass of compound)*100. The lower the total molar mass of the compound, the greater the percent composition of sulfur. In this case, MgS would be that compound, since Mg has the lowest molar mass of the four elements bonded to S.
The answer is false methane is emitted from coal
Answer:
A.) 1.845
Explanation:
You can find the pOH using the following equation:
pOH = -log[OH⁻]
Since NaOH dissociates into 1 Na⁺ and 1 OH⁻, the concentration of both ions is 0.0143 M.
pOH = -log[OH⁻]
pOH = -log[0.0143]
pOH = 1.845
Answer: 1.25 miles per minute
Explanation:
Average speed is the rate of change of total distance covered per unit time.
i.e Average speed = (Total distance / Time taken)
Total distance covered = (25miles + 40 miles + 70 miles + 15 miles)
= 150 miles
Total time taken = ( 15 minutes + 30 minutes + 1 hour + 15 minutes) = 120 minutes
Since 60 minutes = 1 hour, the total time taken is 120 minutes
Now, apply Average speed = (Total distance / Time taken)
= (150 miles / 120 minutes)
= 1.25 miles per minutes
Thus, Joseph drove with an average speed of 1.25 miles per minute.
The answer is (3) metallic. Cobalt is a transition metal, so it can't be covalent bonds, which bond non-metals, therefore eliminating choice 1 and 2. Ionic bonds are between metals and non metals, but solid cobalt does not have a non metal, eliminating choice 4 as well. Metallic bonds are bonds between metals, therefore the answer is (3) metallic.