The atomic number (Z) of the 3 elements F, Ne, and Na, are 9, 10, and 11.
Explanation:
Now Z refers to the number of protons in the element's nucleus, and protons are POSITIVELY charged particles. So a fluoride ion, F−, has 10 electrons rather than 9 (why?), a neutral neon atom has 10 electrons, and a sodium ion, Na+, also has 10 electrons (why?).
So the 3 species are ISOELECTRONIC; they possess the same number of electrons.
You should look at the Periodic Table to confirm the electron number. Elements are (usually) electrically neutral (sometimes they can be ionic if they have lost or gained electrons). If there are 10 positively charged protons in the nucleus, there are NECESSARILY 10 electrons associated with the NEUTRAL atom. I don't know WHY I am capitalizing certain WORDS.
You might ask why sodium will form a positive ion, Na+, whereas F forms a negative ion, F−. This again is a Periodic phenomenon, and explicable on the basis of the electronic structure that the Table formalizes.
Neutral metals tend to be electron-rich species, which have 1 or more electrons in a valence shell remote from the nuclear charge. On the other hand, neutral non-metals have valence electrons in incomplete shells, that do not effectively shield the nuclear charge. The demonstrable consequence is that metals lose electrons to form positive ions, whereas non-metals gain electrons to form negative ions.
Mixture/ compound
hope this helps
Answer:
3.26 % of vinegar is acetic acid
Explanation:
Step 1: Data given
Mass of the sample = 5.54 grams
Volume of NaOH = 30.10 mL
Molarity of NaOH = 0.100M
Step 2: The balanced equation
CH3COOH + NaOH → CH3COONa + H2O
Step 3: Calculate moles NaOH
Moles NaOH = volume * molarity
Moles NaOH = 0.03010 L * 0.100M
Moles NaOH = 0.00301 moles NaOH
Step 4: Calculate moles CH3COOH
For 1 mol NaOH we need 1 mol CH3COOH
For 0.00301 moles NaOH we nee 0.00301 moles CH3COOH
Step 5: Calculate mass CH3COOH
Mass CH3COOH = moles CH3COOH * molar mass CH3COOH
Mass CH3COOH = 0.00301 moles * 60.05 g/mol
Mass CH3COOH = 0.1808 grams
Step 6: Calculate percent by weight of acetic acid
Mass % = ( 0.1808 / 5.54 ) *100%
Mass % = 3.26 %
3.26 % of vinegar is acetic acid
Answer: The correct answer is option B i.e., 2.78 mol
Explanation:
Aluminium reacts with iodine to form Aluminium iodide
From the equation, it is clear that 3 moles of iodine reacts with 2 moles of Aluminium to form Aluminium iodide
We know 
For 2 moles of Aluminium, 
3 moles of Iodine reacts with 54 g of Aluminium
? moles of iodine react with 50 g of Aluminium
