Answer:
C. The balloon with CH4 has the same moles of gas molecules as the balloon with H2
Explanation:
Based on combined gas law, gases under the same pressure, temperature and volume have the same number of moles. With this information we can say the rigth statement is:
<h3>C. The balloon with CH4 has the same moles of gas molecules as the balloon with H2</h3>
Answer:
5.41 ×10⁻²²
Explanation:
We were told right from the question that both the Zinc ions and the Zinc oxide adopts a face-centered cubic arrangement.
Then, the number of ZnO molecule in one unit cell = 4
The standard molar mass of ZnO = 81.38g
Avogadro's constant = 6.023 × 10²³ mole
∴
The mass of one unit cell of zinc oxide can be calculated as:
= 
= 5.40461564×10⁻²²
≅ 5.41 ×10⁻²²
∴ The mass of one unit cell of zinc oxide = 5.41 ×10⁻²²
Answer:
<u>d. a row of elements</u>
Explanation:
Elements that are in the same group, have same number of electrons and make up a column in a periodic table.

Five base SI units that are commonly used in Chemistry; are
1.Metre (m)
2. Kilogram(kg)
3. seconds(s)
4.Kelvins (k)
5. Moles (mol)