Answer:
3. relatively high temperature, about 10,000 K, so that significant numbers of electrons are excited from the ground state, n = 1, to the first excited state, n = 2, but not too many of them have been ejected completely from the atoms
Explanation:
If hydrogen absorption lines are very strong in the visible spectrum of a particular star that means the population of electron in n = 2 is very high so on being exited they absorb radiation in Balmer series and give rise to absorption spectrum. The average temperature required to excite electron in hydrogen atom from n=1 to n = 2 is 10000K .
The correct answer to the question is : 
EXPLANATION :
As per the question, the specific heat of gold is given as c = 
The heat given to the gold dQ = 195 J
The mass of the gold is given as m = 15 gram.
We are asked to calculate the change in temperature.
Let the change in temperature is dT.
We know that dQ = mcdT

[ANS]
Hence, the change in temperature is 100 degree celsius.
Answer:
d = 13 miles
Explanation:
Lets say the position of court house is origin in this case
her office is located at 4 miles west and 4 miles south of court house
so here we have coordinate of the office with respect to court house is given as

now the position of her home is located at 1 miles east and 8 miles north of the court house
so the coordinates of her home is given as

now the change in the position is given as the distance between office and home



There are 60 seconds in a minute.
This means that 5 minutes would be 60 times 5.
60×5 = 300
There are 300 seconds in 5 minutes.
Answer:
Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.