Hence Mg has 10 core electrons and 2 valence electrons. The number of core electrons depends on the period (row) in which the element is found.
Answer:
Frequency = 4.74 × 10¹⁴ Hz
Explanation:
Given data:
Wavelength of light = 633 nm (633 ×10⁻⁹ m)
Frequency of light = ?
Solution:
Speed of light = wavelength × frequency
Frequency = Speed of light / wavelength
Speed of light = 3 × 10⁸ m/s
Frequency = 3 × 10⁸ m/s / 633 ×10⁻⁹ m
Frequency = 0.00474 × 10¹⁷ s⁻¹
Frequency = 4.74 × 10¹⁴s⁻¹
s⁻¹ = Hz
Frequency = 4.74 × 10¹⁴ Hz
Answer:
The new volume of the gas is 21 L.
Explanation:
Volume of a gas is inversely proportional to its pressure at constant temperature such that,
or
We have,
It is required to find V₂. Using above law or Boyle's law such that :
So, the new volume of the gas is 21 L.
Moles of phosphoric acid would be needed : 0.833
<h3>Further explanation</h3>
Given
15 grams of water
Required
moles of phosphoric acid
Solution
Reaction(decomposition) :
H3PO4 -> H2O + HPO3
mol water (H2O :
= mass : MW
= 15 g : 18 g/mol
= 0.833
From the equation, mol ratio H3PO4 = mol H2O = 1 : 1, so mol H3PO4 = 0.833
