You have to use this knwoledge:
1) The superscript number on the left of the symbol is the mass number (A)
2) The underscript number on the left of the symbol is the atomic number (Z)
3) The atomic number, Z, is the number of protons of the atom.
4) The number of electrons of an atoms is equal to the number of protons.
5) The mass number, A is equal to the number of neutrons, N, plus the number of protons, Z, i.e. A = N + Z, from which you obtain N = A - Z
Now I am going to apply above rules to solve the three cases for you.
I will use other notation just because the editor does not permit to place superscripts and underscripts on the left of the symbol.
a) 62 Cu 29 and 62 Zn 39
62 Cu 29:
Z = 29 = number of protons
A = 62 = N + Z => N = 62 - Z = 62 - 29 = 33
Number of electrons = number of protons = 29
62 Zn 39:
Z = 39 = number of protons
A = 62 = N + Z => N = 62 - Z = 62 - 39 = 23
Number of electrons = number of protons = 39
Answers:
protons are not equal
neutrons are not equal
electrons are not equal.
b) 40Ar18 and 41K19
40Ar18:
Z = 18 = number of protons
A = 40 = N + Z => N = 40 - 18 = 22 = number of neutrons
number of electrons = number of protons 18
41K19:
Z = 19 = number of protons
A = 41 = N + Z> N = 41 - 19 = 22
number of electrons = number of protons = 19
Answers:
protons are not equal
neutrons are equal
electrons are not equal
c) 14N7 and 15N7
14N7:
Z = 7 = number of protons
A = 14 => N = 14 - 7 = 7 = number of neutrons
number of elecfrons = number of protons = 7
15N7:
Z = 7 = number of protons
A = 15 => N = 15 - 7 = 8 = number of neutrons
number of electrons = number of protons = 7
Answers:
protons are equal
neutrons are not equal
electrons are equal
Answer:
The answer is
<h2>0.24 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula
<h3>
</h3>
From the question
mass of cork = 2.88 g
volume = 12 mL
The density is
We have the final answer as
0.24 g/mL
Hope this helps you
They can distill the muddy water. This can be done by placing it in a can, covered with pipes to collect the boiling water, and then collecting the distillate. The fuel will be used to provide energy for distillation and the solid particles in from the muddy water will remain in the can as residue.
Answer:
pH = 4.164
Explanation:
The first process is to find the initial moles for the base (B) & the acid (HA)
i.e.
The acid with base reaction is expressed as;
HA + B → A⁻ + HB⁺
to 1.493 × 10⁻³ 2.047 × 10⁻³ - -
- 1.493 × 10⁻³ 1.493 × 10⁻³ 1.493 × 10⁻³ 1.493 × 10⁻³
0 5.54 × 10⁻⁴ 1.493 × 10⁻³ 1.493 × 10⁻³
From observation; both the acid & base weak
Given that:
The pKa for base = 4.594
The pKa for acid = 3.235
Recall that;
pKa = -log Ka
So; Ka =
By applying this:
For Base; Ka = = 2.5468 × 10⁻⁵
For Acid: Ka = = 5.821 × 10⁻⁴
After the reaction; we have the base with its conjugate acid & conjugate base of acid; Thus, since the conjugate acid of the base possesses a higher value of K, it is likely it would be the one to define the pH of the solution.
By analyzing the system, we have:
HB⁺ + H₂O ↔ B + H₃O⁺
to 0.01493 M 0.00554 M
- x x x
0.01493 - x 0.00554 - x x
Thus;
Using the common ion effect;
0.00554 - x 0.00554 &
0.01493 - x 0.01493
∴
x = [H₃O⁺] = 6.8635 × 10⁻⁵
∴
pH = -log(6.8635 × 10⁻⁵)
pH = 4.164
Charle's law states that, v1 / t1 = v2 / t2 .
<span>Hence,v(volume) is directly proportional to t(temperature). </span>
<span>Thus, the volume decreases.</span>