Answer:
John Dalton
Explanation:
John Dalton in 1808 suggested that all matter consists of tiny particles called atoms and that the atoms of a specific element are identical.
He postulated the Dalton's atomic theory which has the following important parts;
- All matters consists of indivisible particles called atoms
- Atoms of the same element are similar and are different from atoms of other elements.
- Atoms can neither be created nor destroyed.
- Atoms combine in simple whole ratios to form compounds.
Answer:
The element with electron configuration 1s² 2s² 2p⁶ will most likely not........
Explanation:
Answer:
The correct option is: b. pH 6.4-8.0
Explanation:
Phenol red is a weak acid that is used as a pH indicator and exists in the form of stable red crystals.
<u>The color of the phenol red solution changes from yellow to red when the change in pH is observed. The color of phenol red transitions from yellow to red when the pH is 6.8 - 8.2 or 6.4 - 8.0</u>
Above the pH of 8.2, the phenol red solution turns a bright pink in color.
Answer:
0.01504 mol/dm3
Explanation:
Calcium Hydroxide - Ca(OH)2
Hydrochloric acid - HCl
The reaction between both is given as;
2HCl + Ca(OH)2 --> CaCl2 + 2H2O
2 : 1
The relationship between the concentration and volume is given as;
CaVa / CbVb = na / nb
where a = acid (HCl) and b = base Ca(OH)2
Inserting the values;
0.04 * 18.8 / (Cb * 25) = 2 / 1
0.752 / 25Cb = 2
Cb = 0.752 / 50 = 0.01504
Answer:
they are both equal
Explanation:
if you don't know don't guess troll the teacher you will get it wrong anyway
