Answer:
The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.
Explanation:
Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.
For example CCl₄ can be shown as follows
..
.. Cl..
.. ..
..Cl..----------C----------..Cl..
..
.. Cl..
The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.
Similarly methane CH4 can also be shown.
The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.
Answer:
I just finished a unit on Scientific Method in my science class! Anyway, it's defined in the screenshots below. Hope this helps!
Answer:
4.5 moles
Explanation:
One mole is equal to 6.022 x 10^23 atoms
2.71 x 10^24 atoms * 1 mol/ 6.022 x 10^23 atoms = 4.5 moles
Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%
