Answer:
100 mL
Explanation:
The reaction that takes place is:
- CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
First we <u>convert 500 mg of CaCO₃ into mmoles</u>, using its <em>molar mass</em>:
- 500 mg ÷ 100 mg/mmol = 5 mmol CaCO₃
Then we <u>convert 5 mmoles of CaCO₃ into HCl mmoles</u>, using the <em>stoichiometric coefficients of the balanced reaction</em>:
- 5 mmol CaCO₃ *
= 10 mmol HCl
Finally we <u>calculate the volume of a 0.10 M HCl solution (such as stomach acid) that would contain 10 mmoles</u>:
- 10 mmol / 0.10 M = 100 mL
Answer:
B. Similar fossils were found in different continents.
Helium
Remember: electron filling of atomic shell ...
The element which have electron in the lowest quantum shell will have the smallest atomic radius\
He:1s1 (Helium)
H:1s2 (hydrogen)
<span>Metallic bonds consist of the attraction of the free-floating valence electrons (negative) for the (positive) metal ions. These bonds are the force of attraction that hold metal together.A piece of pure metal, such as copper or iron, consists of metal atoms surrounded by mobile valence electrons that are free to drift from one part of the metal to another. Metallic bonds result from the attraction between the free-floating valence electrons and the positively charged metal ions.</span>
