The mass number is the total number of protons and neutrons within an atom and since we know that the unknown element has 6 neutrons, we can simply subtract the number of neutrons from the mass number to get the number of protons.
17 - 6 = 11
There are 11 protons in this unknown element.
Extra:
The number of protons (+) and electrons (-) are equal in a neutral atom so since you know that there are 11 protons you also know that there are 11 electrons. On the periodic table, the element with 11 electrons is Na or Sodium.
Hope this helps! :)
Answer:
different number of mass numbers.
Explanation:
isotopes are atoms of the same element having the same atomic number but different mass numbers due to different number of neutrons.
Answer:

Explanation:
From frequency of oscillation

Initially with the suspended string, the above equation is correct for the relation, hence

where k is force constant and m is the mass
When the spring is cut into half, by physics, the force constant will be doubled as they are inversely proportional

Employing f2/ f1, we have

Answer:
27.5 days
0.92 month
Explanation:
= radius of the orbit of moon around the earth = 
= Mass of earth = 
= Time period of moon's motion
According to Kepler's third law, Time period is related to radius of orbit as

inserting the values, we get

we know that
1 day = 24 hours = 24 x 3600 sec = 86400 s

1 month = 30 days
