Answer:
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Explanation:
i would help answer but your post has no diagrams or at least there not showing up
Answer:
The first element in the periodic table is hydrogen.
Explanation:
Hydrogen has an atomic number of one, making it the first element of the periodic table. The atomic number of an element is just the number of protons in the nucleus, so hydrogen has one proton. The neutrons and electrons do not affect the atomic number. After hydrogen with one proton comes helium with two, lithium with three, beryllium with four, and so on.
A heterogeneous mixture since you can separate the ingredients that make it up.
Cobalt is a Transition Element and it has a partially filled d-orbital. As given it has atomic number 27. In neutral state Cobalt has 27 electrons. These electrons are filled in following order,
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁷
Or it can also be written as,
[Ar] 4s², 3d⁷
Where; [Ar] is Argon with electronic configuration 1s², 2s², 2p⁶, 3s², 3p⁶.
Concentration of Ni in 20mL = 5.28ppm x dilution factor = 5.28 x 100/5 = 105.6 ppm = 105.6 mg/L
molar mass of Ni = 58.6934 g
<span>Molarity of Ni = 100.40 x 10^{-3} / 58.6934 = 1.71 x 10^{-3} M = 1.71 mM. </span>
