The given question is incomplete. The complete question is:What is the relative atomic mass of a hypothetical element that consists isotopes in the indicated natural abundances.
Isotope mass amu Relative abundance
1 77.9 14.4
2 81.9 14.3
3 85.9 71.3
Express your answer to three significant figures and include the appropriate units.
Answer: 84.2 amu
Explanation:
Mass of isotope 1 = 77.9
% abundance of isotope 1 = 14.4% = 
Mass of isotope 2 = 81.9
% abundance of isotope 2 = 14.3% = 
Mass of isotope 3 = 85.9
% abundance of isotope 2 = 71.3% = 
Formula used for average atomic mass of an element :

![A=\sum[(77.9\times 0.144)+(81.9\times 0.143)+(85.9\times 0.713)]](https://tex.z-dn.net/?f=A%3D%5Csum%5B%2877.9%5Ctimes%200.144%29%2B%2881.9%5Ctimes%200.143%29%2B%2885.9%5Ctimes%200.713%29%5D)

Therefore, the average atomic mass of a hypothetical element that consists isotopes in the indicated natural abundances is 84.2 amu
The compound sodium carbonate is a strong electrolyte because it completely dissociates when placed in water into its component ions. The equation of the reaction can be expressed as:

The dissociation leads to the formation of sodium and carbonate ions with the latter held together by its internal covalent bond.
This is unlike weak electrolytes that do not dissociate completely in water or aqueous solutions. Only a small fraction of the solute exists as ions in the solution.
More on strong and weak electrolytes can be found here: brainly.com/question/3410548
Answer:
Winnowing
Explanation:
Wind blows the lighter(in terms of mass) chaff from the whole grains,which are heavier(in terms of mass)
<u>Answer:</u> The total pressure inside the container is 77.9 kPa
<u>Explanation:</u>
Dalton's law of partial pressure states that the total pressure of the system is equal to the sum of partial pressure of each component present in it.
To calculate the total pressure inside the container, we use the law given by Dalton, which is:

We are given:
Vapor pressure of oxygen gas,
= 40.9 kPa
Vapor pressure of nitrogen gas,
= 23.3 kPa
Vapor pressure of argon,
= 13.7 kPa
Putting values in above equation, we get:

Hence, the total pressure inside the container is 77.9 kPa
Answer:
The heat of solution is 1.05 kJ/mol
Explanation:
NaOH → Molar mass 40 g/m
This is the mass in 1 mol
Calorimetry formula:
Q = m . c . ΔT
ΔT = T° final - T° initial = 24.5°C - 18.2°C = 6.3°C
mass = 40 g
c = 4.186 kJ/kg°C (the same as water)
So we have to convert 40 g to kg
40 g/1000 = 0.04 kg
Q = 0.04 kg . 4.186 kJ/kg°C . 6.3 °C = 1.05 kJ