The answer to this problem is =12
Answer:
Option A, The Rutherford experiment proved the Thomson "plum-pudding" model of the atom to be essentially correct.
Explanation:
Thomson's plum pudding model:
Plum pudding model was proposed by J.J Thomson. In Thomson's model, atoms are proposed as sea of positively charge in which electrons are distributed through out.
Result of Rutherford experiment:
As per Rutherford's experiment:
Most of the space inside the atom is empty.
Positively charge of the atom are concentrated in the centre of the atom known as nucleus.
Electrons are present outside the nucleus and revolve around it.
As it is clear that, result of Rutherford experiment did not supported the Thomson model.
Answer:
In order to answer the question, we convert the measurements given to a common base unit. For this case, we use seconds.
A) 0.02 seconds
B) 0.02 teraseconds x (10^12 s / 1 terasecond) = 2x10^10 seconds
C) 2,500 milliseconds x (1 s / 1000 ms) = 2.5 seconds
D) 25,000 nanoseconds x (1 x 10^-9 s / 1 nanosecond) = 2.5 x 10^-5 seconds
So ,The correct answer is option " D "
To calculate the number of atoms of Cr, we first find the number of moles per unit of cubic centimeter of Cr. Then, use avogadros number for the number of atoms. Calculations are as follows:
1 cm^3 (7.15 g/cm^3) (1 mol / 51.996 g Cr) = 0.14 mol Cr
0.14 mol Cr ( 6.022 x 10^23 atoms Cr / 1 mol Cr ) = 8.28 x 10^22 atoms Cr
