Answer:
20.2 amu.
Explanation:
Let A represent isotope ²⁰X
Let B represent isotope ²²X
From the question given above, the following data were obtained:
For Isotope A (²⁰X):
Mass of A = 20
Abundance (A%) = 90%
For Isotope B (²²X):
Mass of B = 22
Abundance (A%) = 10%
Relative atomic mass (RAM) =?
The relative atomic mass (RAM) of the element can be obtained as follow:
RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]
RAM = [(20 × 90)/100] + [(22 × 10)/100]
RAM = 18 + 2.2
RAM = 20.2 amu
Thus, relative atomic mass (RAM) of the element is 20.2 amu
Protons have a mass of 1
Neutrons have a mass of 1
So 13*1 + 14*1 = Mass number 27
Answer: Fire requires oxygen to burn. Water "smothers" fire and prevents it from acquiring more oxygen. Fire also requires heat, which cool water may prevent/remove.
Neon belongs to 2nd Period & 18th Group
Answer:
1.44 x 10²⁵ ions of Na⁺
Explanation:
Given parameters:
Mass of NaCl = 1.4kg = 1400g
Unknown:
Number of ions of sodium = ?
Solution:
The compound NaCl in ionic form can be written as;
NaCl → Na⁺ + Cl⁻
In 1 mole of NaCl we have 1 mole of sodium ions
Now, let us find the number of moles in NaCl;
Number of moles =
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of moles =
= 23.93mol
So;
Since 1 mole of NaCl gives 1 mole of Na⁺
In 23.93 mole of NaCl will give 23.93 mole of Na⁺
1 mole of a substance = 6.02 x 10²³ ions of a substance
23.93 mole of a substance = 6.02 x 10²³ x 23.93
= 1.44 x 10²⁵ ions of Na⁺