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3 years ago

How to identify the number of protons neutrons and electrons and mass number?

1 answer:

5 0

1. Look at the atomic number of the element(located in upper left corner of the element box).This number represent the number of protons of the element.In same of the elements the number of electrons and protons are the same. in other (negative) you have to calculate
2. Look at the atomical mass( located underneath the element, which is a sum of neutrons and protons.Round the mass to the whole number and substract the atomic number. That will be number of neutrons.

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Lewis structures for the perchlorate ion (ClO4−) can be drawn with all single bonds or with one, two, or three double bonds. Dra

Vanyuwa [196]

Answer:

The most important resonance structure is 4 (attached picture). Its bon order is $\frac{7}{4}$ or $1\frac{3}{4}$ .

Explanation:

A picture with 4 forms of the perchlorate structure is attached. The first structure has simple bonds. The second structure contains a double bond, the third structure has two double bonds and the fourth structure has three double bonds.

Formal charge = group number of the periodic table - number of bonds (number of bonding electrons / 2) - number of non-shared electrons (lone pairs)

The formal charges in the first structure is +3 in chlorine and -1 in oxygen.

The formal charges in the second structure is +2 in chlorine, -1 in oxygen and 0 in the double bond oxygen.

The formal charges in the third structure is +1 in chlorine, -1 in the single bond oxygens and 0 in the double bond oxygens.

The formal charges in the fourth structure is 0 in chlorine, -1 in the single bond oxygen and 0 in the double bond oxygens.

The most important resonance structure is given by:

Most atoms have 0 formal charge.

Lowest magnitude of formal charges.

If there is a negative formal charge, it's on the most electronegative atom.

Hence, the fourth structure is the mosr important.

The bond order of the structure is:

Total number of bonds: 7

Total number of bond groups: 4

Bond order= $\frac{7}{4} =1\frac{3}{4}$

5 0

3 years ago

__________ is considered to be the greatest solvent in the world because it can dissolve so many substances.

allochka39001 [22]

The correct answer is c. water.

6 0

3 years ago

If water and hydrogen peroxide both consist of hydrogen and oxygen atoms, explain why they have different chemical and physical

lana [24]

Water and hydrogen peroxide are different compounds although they have the same kind of atoms. The molecular formula of water is H2O (two atoms of oxygen chemically bonded to one atom of oxygen). The molecular formula of hydrogen peroxide is H2O2, (each atom of oxygen is chemical bonded to one atom of H and other atom of O). So,<span> the presence of different chemical bonds leads to different products with different chemical properties.</span><span />

5 0

3 years ago

How many grams would 3.36 × 1023 molecules of copper (II) sulfate (CuSO4) weigh?

Semenov [28]

Molar mass ( CuSO₄) = 159.609 g/mol

159.609 g ----------------- 6.02 x 10²³ molecules
? g ------------------ 3.36 x 10²³ molecules

mass = ( 3.36 x10²³) x 159.609 / 6.02 x 10²³

mass = 5.36 x 10²⁴ / 6.02 x 10²³

mass = 8.90 g

hope this helps!

3 0

3 years ago

Read 2 more answers

How many grams of h2 are needed to produce 10.78 g of nh3?

balu736 [363]

Ammonia is formed by a reaction between hydrogen and nitrogen as shown by the equation below.
N2(g) + 3H2(g) = 2NH3(g)
1 mole of ammonia contains 17 g
Therefore 10.78 g of ammonia are equivalent to 10.78/17 = 0.6341 moles
The mole ratio of hydrogen to ammonia is 3 : 2
Therefore, moles of hydrogen used will be 0.6341 × 3/2 = 0.9512 moles
1 mole of hydrogen is equivalent to 2 g
Thus, the mas of hydrogen will be 0.9512 moles × 2 = 1.9023 g

6 0

4 years ago