I believe Mendeleev formed his periodic table by atomic weight (nowadays we do it by atomic number) so he likely used those values.
Atomic mass Cu = 63.546 a.m.u
63.546 g ---------------- 6.02x10²³ atoms
22 g --------------------- ??
22 x (6.02x10²³ ) / 63.546 => 2.08x10²³ atoms
hope this helps!
Answer:
B. Aluminum is a good conductor of heat
Explanation:
Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. The Physical Properties of Aluminum are as follows: Color : Silvery-white with a bluish tint.
<span>The correct answer is the first option. Electron is not found in the nucleus of an atom. The sub-atomic particles of an atom are the
proton, electron and the neutron. An electron has a charge of -1 and a
smaller mass than a proton. Proton has the same mass with the neutron. The
ratio between the mass of a proton and an electron is about 2000. An electron
has an equal value but negative charge with the proton.</span>
Answer : The mass of oxygen per gram of sulfur for sulfur dioxide and sulfur trioxide is, 0.997 g and 1.5 g respectively.
Explanation : Given,
Mass of oxygen in sulfur dioxide = 3.49 g
Mass of sulfur in sulfur dioxide = 3.50 g
Mass of oxygen in sulfur trioxide = 9.00 g
Mass of sulfur in sulfur trioxide = 6.00 g
Now we have to calculate the mass of oxygen per gram of sulfur for sulfur dioxide and sulfur trioxide.
Mass of oxygen per gram of sulfur for sulfur dioxide = 
Mass of oxygen per gram of sulfur for sulfur dioxide = 
and,
Mass of oxygen per gram of sulfur for sulfur trioxide =
Mass of oxygen per gram of sulfur for sulfur trioxide = 
Thus, the mass of oxygen per gram of sulfur for sulfur dioxide and sulfur trioxide is, 0.997 g and 1.5 g respectively.
