Hope my answer helped you
D. To answer this question refer to the periodic table and think logically about it. Adding one proton increases the atomic number so you go along the row to Nitrogen. If you lose one neutron then the atomic mass decreases by 1 so 14-1 is 13.
Answer:
The correct answer is option A, that is, one valence electron in its third energy shell and option C, that is, 11 electrons and 11 protons.
Explanation:
The outermost electrons and the ones that take part in the process of bonding are termed as valence electrons. The atomic number of sodium is 11, thus, it possesses 11 protons and the atoms are neutral so it suggests that sodium has 11 electrons. By electronic configuration, it can be seen that in sodium, two electrons are present in the first shell, 8 in the second, and only one electron in the third shell, that is, 2.8.1. The electron present in the third shell is the valence electron.
- Get 3 cups of water at the exact same temperature, using the thermometer to check.
- Label the cups as ‘whole’, ‘pieces’, and ‘crushed’
- Next, get something to dissolve, in this case, polident. Take one of the polident tablets and break it into 4 pieces, and set it aside.
- Take another polident tablet and this time put it into a different cup, and crush it. Set it aside.
- Keep the last tablet whole.
- Set up your stopwatch and drop the polident tablet that is whole in the cup labeled ‘whole’, starting the stopwatch at the same time.
- Watch the cup and see when the tablet is fully dissolved, then stop the stopwatch.
- Record the time in the table.
- Repeat steps 6-8 for both the ‘pieces’ and ‘crushed’ tablets.
Hope this helps! Please let me know if you need more help, or if you think my answer is incorrect. Brainliest would be MUCH appreciated. Have a great day!
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Answer:
Mass = 157.5 g
Explanation:
Given data:
Mass of CO needed = ?
Mass of Fe formed = 209.7 g
Solution:
Chemical equation:
3CO + F₂O₃ → 2Fe + 3CO₂
Number of moles of Fe:
Number of moles = mass/ molar mass
Number of moles = 209.7 g/ 55.85 g/mol
Number of moles = 3.75 mol
Now we will compare the moles of iron and carbon monoxide.
Fe : CO
2 : 3
3.75 ; 3/2×3.75 = 5.625 mol
Mass of CO:
Mass = number of moles × molar mass
Mass = 5.625 mol × 28 g/mol
Mass = 157.5 g
