Answer:
Four covalent bonds.
Explanation:
Hello,
In this case, given the attached picture in which you can find the Lewis dot structure for metanal (formaldehyde) we can see two C-H bonds and two C-O bonds via a double bond, thus, we can compute the type of each bond given the electronegativities of hydrogen, carbon and oxygen which are 2.1, 2.5 and 3.5 respectively:

Thus, since both electronegativity difference are less 1.7 we infer that all of them are covalent, therefore, it has four covalent bonds, two C-H bonds and a double C-O bond.
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Answer:
Number of particles = 2.0 g*(6.0 x 10^23 particles/mol) / 20.18 g/mol
Option C is correct
Explanation:
Step 1: Data give
Mass of Ne = 2.0 grams
Molar mass of neon = 20.18 g/mol
Number of Avogadro = 6.0 *10^23 /mol
Step 2: Calculate number of moles of neon
Moles Ne = Mass of ne / Molar mass of ne
Moles Ne = 2.0 / 20.18 g/mol
Moles Ne = 0.099 moles
Step 3: Calculate nulber of particles
Number of particles = 6.022*10^23 / mol * 0.099 moles = 5.96 *10^22
Number of particles = 6.022*10^23 * (2.0g/ 20.18g/mol)
Number of particles = 2.0 g*(6.0 x 10^23 particles/mol) / 20.18 g/mol
Option C is correct
Answer:
Option D. Al is above H on the activity series.
Explanation:
The equation for the reaction is given below:
2Al + 6HBr —> 2AlBr₃ + 3H₂
The activity series gives us a background understanding of the reactivity of elements i.e how elements displace other elements when present in solution.
From the activity series of metals, we understood that metal higher in the series will displace those lower in the series.
Considering the equation given above, Al is higher than H in the activity series. Thus, the reaction will proceed as illustrated by the equation.
Therefore, we can conclude that the reaction will only occur if Al is higher than H in the activity series.