Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
Absorbance measures the ability of the substance to absorb light at a specific wavelength.
Absorbance is also equal to the product of molar absorptivity, path length and molar concentration.
The mathematical expression is given as:
(1)
where, A = absorbance
= molar absorptivity
l = path length
c = molar concentration.
The above formula is said to Beer's Law.
Absorptivity of protein x = 
Path length = 1 cm
Molar concentration = 
Put the values in formula (1)
= 
Thus, absorbance at 280 nm =
Distilled water and sealed container are in equilibrium when these objects do not exchange more heat.
<h3>What is thermal equilibrium?</h3>
The expression 'thermal equilibrium' makes references to the phenomenon by which two objects interact with each other to exchange heat energy.
Objects in contact can transfer heat to reach a thermal equilibrium state where the temperature is the same for both objects.
In conclusion, distilled water and sealed container are in equilibrium when these objects do not exchange more heat.
Learn more on thermal equilibrium here:
brainly.com/question/9459470
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Answer:
(B) 2AgCl + sunlight → Cl2 + 2Ag (decomposition reaction) is correct option.
