Exclusion Principle: How many electrons can be found with principal quantum number n = 3 in a suitably heavy atom?
A. 18
B. 6
C. 20
D. 9
Answer: A
You might also like to view...
It is found that lead from 2-mm-thick old paint on a certain wood surface has permeated to 1000 ppm at a depth of 2 mm below the outer wood surface. If the paint contains 20% (by mass) lead and was applied 20 years before the lead content to the wood was measured, estimate the diffusivity of the lead into the wood if it is found that the paint has lost 50% of the original amount of the lead. Assume that the lead did not diffuse into the air. Wood may be approximated as cellulose, C6 H10 O5, with molecular weight of 116, lead has molecular weight of 207, and the paint density may be taken as 1020 kg/m^3 when new.
What will be an ideal response?
Significant Figures: In the sum A + B + C, A is accurate to 5 decimal places, B is accurate to 2 decimal places, and C is accurate to 3 decimal places. What is the correct number of decimal places in the sum?
A. 2 B. 3 C. 4 D. 5 E. 10
If the acceleration vector of an object is directed parallel to the velocity vector, then
A) the object is speeding up. B) the object is slowing down. C) the object is moving with a constant velocity. D) the object is turning. E) the object is at rest.
Any main-sequence star over 25 solar masses will probably retain enough matter in its core after its supernova to make a black hole
Indicate whether the statement is true or false