Answer: A and D
Explanation: isotopes must have same atomic number but different mass number due to the difference in their Neutron number
South east should be the answer
Answer:
Option (B)
Explanation:
Crystals are usually defined as those substances that are comprised of atoms, ions, and molecules, and they are oriented in a very well-developed and ordered microscopic structure. These crystals are interlinked to one another by strong chemical bonds, namely the metallic, covalent, ionic and Vander Waals bond. In nature, these crystals form when any liquid undergoes cooling and solidifies.
The study of crystals is commonly known as crystallography and is directly associated with the minerals.
Thus, the correct answer is option (B).
Answer:
57 mL
Explanation:
To make things clear, when 769 mL of ethanol were mixed with 507 mL of water, the resulting volume was not (769+507) 1276 mL, but a lower value. This is because of the interactions between liquid molecules.
First we<u> calculate how many grams of ethanol are there in 769 mL</u>, using the <em>given density</em>:
- 0.7893 g/mL * 769 mL = 606.97 g ethanol
Then we<u> convert 606.97 g of ethanol into moles</u>, using its<em> molar mass</em>:
- 606.97 g ÷ 46.07 g/mol = 13.17 mol
Now we <u>calculate the actual volume of the solution</u>, using the <em>definition of molarity</em>:
- Volume = Moles / Molarity
- 13.17 mol / 10.8 M = 1.219 L
Finally we <em>convert 1.219 L to mL</em>, and <u>calculate the difference in volume</u>:
- 1276 mL - 1219 mL = 57 mL