Answer:
Here's what I get
Explanation:
You want to dilute the original solution by a factor of 25 in two steps, so you could dilute it by a factor of 5 in the first step, then dilute the new solution by another factor of 5.
A. First dilution
Use a 10 mL pipet to transfer 10 mL of the original solution to a 50 mL volumetric flask. Make up to the mark with distilled water. Shake well to mix.
Use the dilution formula to calculate the new concentration.

B. Second dilution
Repeat Step 1, using the 0.003 970 mol·L⁻¹ solution.

3. Check:
Compare the final concentration with the original

Answer:
Bicarbonate, the conjugate base of carbonic acid.
Explanation:
Answer:
hydrogen (H), nitogen (N), oxygen (O), fluorine (F), chlorine (Cl), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn)
Explanation: found this online, it's best to remember them.
Chemistry is the study of substances—that is, elements and compounds.