Answer:
3.94 × 10³ g
Explanation:
Step 1: Write the neutralization reaction
HClO₃ + NaOH = NaClO₃ + H₂O
Step 2: Calculate the moles of chloric acid that react
25.5 L of 3.86 M chloric acid is to be neutralized. The reacting moles are:

Step 3: Calculate the required moles of sodium hydroxide
The molar ratio of HClO₃ to NaOH is 1:1. Then, the reacting moles of NaOH are 98.4 moles.
Step 4: Calculate the mass of sodium hydroxide corresponding to 98.4 moles
The molar mass of NaOH is 40.00 g/mol.

For #7, both hydrogen and oxygen are nonmetals, making it not A,
B would be the correct answer
For #8, chemical properties is the characteristic of a substance observed in a chemical reaction, A and B would be physical. C would be correct
hope this helped
The missing isotope in the equation is going to have the atomic mass and atomic number as the difference between the numbers of the other isotopes mass and atomic number respectively.
atomic mass 210-206= 4
atomic number 84-82= 2
the symbol has to correspond to the element with the atomic number. In this case 2 = He
2. CO
3.O2
4.NH3
5.NO
6.NO2
7.CO2
8.H2