Answer:In chemistry, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
Explanation: hope this helped
Answer:
A = 65.46 u
Explanation:
Given that,
The composition of zinc is as follows :
Zn-64 = 48.63%
Zn-66 = 27.90%
Zn-67 = 4.10%
Zn-68 = 18.75%
Zn-70 = .62%
We need to find the average atomic mass of the given element. It can be solved as follows :
So, the average atomic mass of zinc is 65.46 u.
Answer: 4.96 moles
Explanation:
C5H12 is the chemical formula for pentane, the fifth member of the alkane family.
Given that,
number of moles of C5H12 = ?
Mass in grams = 357.4 g
Molar mass of C5H12 = ?
To get the molar mass of C5H12, use the atomic mass of carbon = 12g; and Hydrogen = 1g
i.e C5H12 = (12 x 5) + (1 x 12)
= 60g + 12g
= 72g/mol
Now, apply the formula
Number of moles = Mass / molar mass
Number of moles = 357.4g / 72g/mol
= 4.96 moles
Thus, 4.96 moles of C5H12 that are contained in 357.4 g of the compound.
Answer:
- <em>The solution expected to contain the greatest number of solute particles is: </em><u>A) 1 L of 1.0 M NaCl</u>
Explanation:
The number of particles is calculated as:
a) <u>For Ionic compounds</u>:
- molarity × volume in liters × number of ions per unit formula.
b) <u>For covalent compounds</u>:
- molarity × volume in liters
The difference is a factor which is the number of particles resulting from the dissociation or ionization of one mole of the ionic compound.
So, calling M the molarity, you can write:
- # of particles = M × liters × factor
This table show the calculations for the four solutions from the list of choices:
Compound kind Particles in solution Molarity # of particles
(dissociation) (M) in 1 liter
A) NaCl ionic ions Na⁺ and Cl⁻ 1.0 1.0 × 1 × 2 = 2
B) NaCl ionic ions Na⁺ anc Cl⁻ 0.5 0.5 × 1 × 2 = 1
C) Glucose covalent molecules 0.5 0.5 × 1 × 1 = 0.5
D) Glucose covalent molecules 1.0 1.0 × 1 × 1 = 1
Therefore, the rank in increasing number of particles is for the list of solutions given is: C < B = D < A, which means that the solution expected to contain the greatest number of solute particles is the solution A) 1 L of 1.0 M NaCl.
5.75g
Explanation:
Given parameters:
Number of atoms = 1.505 x 10²³atoms
let us find the number of moles and mass of this atom.
Solution:
The mole is convenient unit for reporting measurements in chemistry. It allows us to make mathematical calculations:
one mole of substance contains 6.02 x 10²³atoms
Number of moles of Na given = 
= 0.25moles
Mass of Na atom given = number of moles x molar mass
Molar mass of Na= 23g/mole
Mass of Na = 0.25 x 23 = 5.75g
learn more:
Number of moles brainly.com/question/1841136
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