After 1911 most scientists accepted<span> the </span>theory<span> that the </span>nucleus<span> of an </span>atom<span> was </span>very dense<span> and </span>very small<span> and </span>has<span> a </span>positive charge<span>. </span>
Answer: The correct answer is option(A).
Explanation:
Total forces exerting on the car = F
= Force on car exerting in right direction
= Force on car exerting in left direction
= Force on car exerting in upward direction
= Force on car exerting in downward direction

(negative sign shows the direction)
Since, upward force are equal in magnitude but opposite in direction by which they will balance out each other.so, the net force car will be due to two forces
and 
(negative shows the direction)
The magnitude (size) and direction of the cumulative force acting on the car will 30 N towards right direction.Hence, correct answer is option(A).
Answer:
Explanation:
19) it is 3d10 instead of 4d10
20) it is missing 3p6, and 4s2 before 3d5
21) Ra is not a noble gas
22) Cs is not a noble gas
It is called a dactyloscopy
Answer:
0.5188 M or 0.5188 mol/L
Explanation:
Concentration is calculated as <u>molarity</u>, which is the number of moles per litre.
***Molarity is represented by either "M" or "c" depending on your teacher. I will use "c".
The formula for molarity is:
n = moles (unit mol)
V = volume (unit L)
<u>Find the molar mass (M) of potassium hydroxide.</u>

<u>Calculate the moles of potassium hydroxide.</u>


Carry one insignificant figure (shown in brackets).
<u>Convert the volume of water to litres.</u>


Here, carrying an insignificant figure doesn't change the value.
<u>Calculate the concentration.</u>

<= Keep an insignificant figure for rounding
<= Rounded up
<= You use the unit "M" instead of "mol/L"
The concentration of this standard solution is 0.5188 M.