Explanation:
The scientists realized that the properties of elements related to each other depending on relational properties of their atoms. They realized that atoms of different elements shared some properties depending on the number of electrons they have in their valence orbital shells and atomic mass numbers. These atomic properties determined the elements' shared properties such as texture, reactivity, electric conductivity and etcetera. Arranging the atoms in a periodic table would therefore ideally make it easier to decipher the shared similarities and differences between atoms of different elements, such as physical and chemical properties.
Learn More:
For more on the periodic table check out these questions;
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Answer:
The correct answer is D.They have stars that may appear to wobble.
Explanation:
Binary star - Wikipediaen.wikipedia.org › wiki › Binary_star
''Astronomers have discovered some stars that seemingly orbit around an empty space. Astrometric binaries are relatively nearby stars which can be seen to wobble around a point in space, with no visible companion. The same mathematics used for ordinary binaries can be applied to infer the mass of the missing companion''
<em>-Wikipediaen.wikipedia.org › wiki › Binary_star</em>
<em>-Edge 2021</em>
<em>might be a lil late but YW
</em></p>
6a. physical reaction
6b. endothermic reaction
7a. physical reaction
7b. the reactants are carbon dioxide, water and light energy. the product is starch
7c. exothermic reaction
6.11% w/v of Cu2+ implies that 6.11 g of Cu2+ is present in 100 ml of the solution
therefore, 250 ml of the solution would have: 250 ml * 6.11 g/100 ml = 15.275 g
# moles of Cu2+ = 15.275 g/63.546 g mole-1 = 0.2404 moles
1 mole of CuCl2 contain 1 mole of Cu2+ ion
Hence, 0.2404 moles of Cu2+ would correspond to 0.2404 moles of CuCl2
Molar mass of CuCl2 = 134.452 g/mole
The mass of CuCl2 required = 0.2404 moles * 134.452 g/mole = 32.32 grams
Answer: The energy of the 4-s subshell is lower than the energy of 3-d subshell.
Explanation:
During the filling of electrons in subshells, the lower energy levels are filled before the higher energy levels. Also known as Aufbau principle.
Energy of the sublevel = (n + l)
where : n = Principal quantum number
l = Azimuthal quantum number(s=0,p=1,d=2,f=3)
Energy of 4-s subshell= (4+0) = 4
Energy of 3-d subshell=(3+2) = 5
Energy of 4-s subshell is lower than the energy of 3-d subshell, that is why 4s orbital is filled before the 3-d subshell.
