Answer:
36
Explanation:
Since the sample was undiluted the number of colonies is the number that grew on the nutrient agar which is 36 colonies. If it was diluted for example let say 0.1 ml from a dilution in which 1 ml of the sample was added to 9 ml of water, and it grew colonies then 0.1 ml yielded 6 colonies, 1 ml of the diluted sample will yield 60 colonies and 10 ml will have 600 colonies and therefore the 1 ml undiluted sample will have 600 colonies.
Isoelectronic means equal number of electrons.
O+ is formed when the atom of O loses 1 electron.
The number of electrons of neutral O atom equals its number of protons.
Number of protons identifies the atomic number and position of the element in the periodic table.
The positon of O in the periodic table is A = 8, so it has 8 electrons and O+ has 8 - 1 = 7 electrons.
The neutral atom with one electron less than O is of the element to the left of O in the periodic table (A = 7). That element is N.
Therefore, the neutral atom isoelectronic with O+ is N (both have 7 electrons).
Answer:
Abundance of 32S is 94.41%
Explanation:
The average atomic mass is defined as the sum of the atomic masses of each isotope times its abundance:
Average atomic mass = ∑ Atomic mass istope*Abundance
For the sulfur:
32.07amu = 31.97207X + 32.97146Y + 33.96786*0.0422 <em>(1)</em>
<em>Where X is abundance of 32S and Y abundance of 33S</em>
Also we can write:
1 = X + Y + 0.0422 <em>(2)</em>
0.9578 - X = Y
Because the sum of the abundances = 1
Replacing (2) in (1):
32.07amu = 31.97207X + 32.97146(0.9578 - X) + 33.96786*0.0422
32.07 = 31.97207X + 31.58006 - 32.97146X + 1.43344
-0.9435 = -0.99939X
0.9441 =X
In percentage, abundance of 32S is 94.41%
Answer:
Explanation:
The main task here is that there are some missing gaps in the above question that needs to be filled with the appropriate answers. So, we are just going to do rewrite the answer below as we indicate the missing gaps by underlining them and making them in bold format.
SO; In the quantum-mechanical model of the hydrogen atom.
As the n level increases. the energy <u>increases</u> and thus levels are <u>closer to </u>each other. Therefore, the transition <u>3p→2s</u> would have a greater energy difference than the transition from <u>4p→3p.</u>
Answer:
The H+ (aq) concentration of the resulting solution is 4.1 mol/dm³
(Option C)
Explanation:
Given;
concentration of HA, 
= 6.0mol/dm³
volume of HA, 
= 25.0cm³, = 0.025dm³
Concentration of HB, 
= 3.0mol/dm³
volume of HB, 
= 45.0cm³ = 0.045dm³
To determine the H+ (aq) concentration in mol/dm³ in the resulting solution, we apply concentration formula;
where;
is initial concentration
is initial volume
is final concentration of the solution
is final volume of the solution
Therefore, the H+ (aq) concentration of the resulting solution is 4.1 mol/dm³
