78 and 78. An atom of the element has 78 electrons and 78 protons.
The atomic number is 78, so the atom has 78 protons (+).
If the atom is neutral, it must contain 78 electrons (-).
Answer:
Water has the greatest ΔEN
ΔEN H₂O → 3.4 - 2.1 = 1.3 Option D.
Explanation:
We should find the Electronegativity data in the Periodic table for all the elements:
C : 2.6
O: 3.4
H: 2.1
S: 2.6
N: 3.0
a. ΔEN CO₂ → 3.4 - 2.6 = 0.4
b. ΔEN H₂S → 2.6 - 2.1 = 0.5
c. ΔEN NH₃ → 3 - 2.1= 0.9
d. ΔEN H₂O → 3.4 - 2.1 = 1.3
Answer:
Option a. 4 g of He
Explanation:
6.02×10²³ is the Avogadro's number. The amount of units that corresponds to 1 mol, in this case the units are molecules.
Let's find out which mass corresponds to 1 mol (mass / molar mass)
a. 4g / 4g/mol = 1 mol He
b. 14g / 6.94 g/mol = 2.01 mol Li
c. 80g /159.8 g/mol = 0.5 moles Br₂
d. 4g / 2g/mol = 2 mol H₂