The primary reason for this was that Mendeleev
didn't know that atomic numbers actually existed. Atomic numbers
were only discovered a period after Mendeleev's time. The use of X-rays made it
possible to find the atomic number, and those had not been discovered yet. <span>
<span>The periodic table was then arranged in 1913 by Henry Moseley
in an arrangement according to atomic number.</span></span>
Answer:
<h3>The answer is option B</h3>
Explanation:
To calculate the number of atoms we must first calculate the number of moles
Molar mass = mass / number of moles
number of moles = mass / Molar mass
Molar mass (K) = 39.10mole
mass = 2.10g
number of moles = 2.10/ 39.10
= 0.0537mol
After that we use the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10^23 entities
Number of K atoms is
N = 0.0537 × 6.02 × 10^13
<h3>N = 3.23×10^22 atoms of K</h3>
Hope this helps you.
A displacement reaction (also known as a replacement reaction) is when one element is replaced by another compound. Ex) Fe+CuSO4=FeSO+Cu
Answer:
A) pH of Buffer solution = 4.59
B) pH after 5.0 ml of 2.0 M NaOH have been added to 400 ml of the original buffer solution = 4.65
Explanation:
This is the Henderson-Hasselbalch Equation:
to calculate the pH of the following Buffer solutions.
Answer:
Aluminum is a shiny, silvery white colored metal that is light in weight and strong. Th density of aluminum is 2.7 g/mL, which means the metal will sink in water, but is still relatively light
Hope this helps (:
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