Detailed solutions and explanations please. 1. How many protons, neutrons, and e

Question

Detailed solutions and explanations please. 1. How many protons, neutrons, and electrons are contained in an atom (ion)? a) 4oAr Answer: - p; - n; - e b) 56Fe2+ Answer: - p; - n; - e c) Write the symbol of a neutral atom (in the AE z form) which has 14 electrons and 16 neutrons. Answer: 2. Determine the number of moles of N atoms in 55 g of (as always, pay attention to # of sig.fig.) 3. a) Convert into Joules the energy of 1.23 MJ. 1.23 MJ = J b) Convert into liters the volume of 2.46 mL. 2.46 mL = L 4. The two naturally occurring isotopes of chlorine (35C1 and 37C1) have masses of 34.9689 and 36.965 8 u, respectively. Determine the percentage of 37Cl in naturally occurring chlorine. Calculate the value to the maximum precision possible with the given data (correct number of significant figures is required). 5. Determine the empirical formula of the compound having the following mass percents: 6. A 0.3654-g sample of a carbon-hydrogen-oxygen compound yields 1.0420 g C02 and 0.2437 g H20 in combustion analysis. The molecular mass of this compound is 108.1 u. Determine its a) empirical and b) molecular formulas.

Explanation / Answer

In general;

The atomic number is the number of protons in an atom of an element.

Atoms must have equal numbers of protons and electrons.

Mass Number = (Number of Protons) + (Number of Neutrons)

a)

40Ar

The atomic number of Ar is 20 means the number of protons in Ar is 20.

Atoms must have equal numbers of protons and electrons. Therefore the number of electronsin Ar is also 20.

Mass Number = (Number of Protons) + (Number of Neutrons)

Number of Neutrons = 40-20 =20.

b)

56Fe2+

Atomic no. of Fe (Z)=26
Mass no. of Fe (A)=56

Therefore, no. of protons in Fe2+=Z=26
No, of neutrons in Fe2+=A-Z=56-26=30

No. of electrons in 56Fe2+=Z - ionic charge=26-2=24 (since 56Fe2+ is a cation).

c)

Here, number of electrons are 14 and neutrons are 16

Atoms must have equal numbers of protons and electrons. Hence the numbers of protons are 14.

Mass Number = (Number of Protons) + (Number of Neutrons)      

Mass Number = 14+16=30

with 14 number of electrons the element is Si, silicon.

now write the element in the form of AEZ as follows:

14Si30

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.