Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.
1. Something that is magnetic has magnetic fields. The fields start at the North Pole and go around the magnet, and terminate at the south pole of the magnet. All <span>magnetic substances have north and south poles.
2. A</span>n electric field is the area that surrounds an electric charge an magnetic field is the are of the force around the magnetic poles it is induced by <span>emf.</span>
Answer:
The atomic mass of Si-30 is 29.955 amu
Explanation:
Step 1: Data given
Si-28 has an atomic mass of 27.9769 amu and a natural abundance of 92.2 %
Si-29 has an atomic mass of 28.9765 amu and a natural abundance of 4.67%
The atomic mass of Si is 28.0855 amu
Step 2: Calculate natural abundance of Si-30
100% - 92.2 % - 4.67% = 3.13 %
0.922 * 27.9769 + 0.0467 * 28.9765 + 0.0313* X = 28.0855
27.14790435 + 0.0313X = 28.0855
0.0313X = 0.93760
X = 29.955 amu
The atomic mass of Si-30 is 29.955 amu
The amount of atoms of Phosphorus in 3.80 mol of copper (II) phosphate would be equivalent with :
3.80 mol x (6.022 x 10^23 molecules)/ (1 mol)
Hope this helps
Answer:
14
73%
Explanation:
The mean Number of years worked :
. (sum of service years) / employees in the
(8+13+15+3+13+28+4+12+4+26+29+3+10+3+17+13+15+15+23+13+12+1+14+14+17+16+7+27+18+24) /
(417 / 30)
= 13.9 years
= 14 years
The percentage of employees who have worked for atleast 10 years :
Number of employees with service years ≥ 10 years = 22 employees
Total number of employees
Percentage (%) = (22 / 30= * 100% = 0.7333 * 100% = 73.33% = 73%