Answer:
B. -2
Explanation:
The total charge on an atom is the sum of all individual charges present in it. Therefore, the total charge on this atom is given by the following formula:

where,
q = total charge on atom = ?
= no. of protons in the atom = 15
= no. of electrons in the atom = 17
= no. of neutrons in the atom = 12
= charge on proton = +1
= charge on electron = -1
= charge on neutron = 0
Therefore,

Hence the correct option is:
<u>B. -2</u>
This is not as simple as it looks.
His average speed is NOT (10km/hr + 50km/hr)/2 = 30 km/hr.
You have to use the definition of speed:
Speed = (total distance covered) / (time to cover the distance).
Let's say the distance up (and down) the hill is 'd' .
Then the time it takes to go up the hill is (d/10) hours.
And the time it takes to come down the hill is (d/50) hours.
Total distance = 2d km
Total time = (d/10) + (d/50) = (5d/50) + (d/50) = 6d/50
Speed = distance/time = 2d/(6d/50) = 100d/6d
<em>Speed = </em>100/6 = <em>16-2/3 km/hr</em>
Answer:
Latent heat
Latent heat is the heat needed to change a state without a change in temperature.
Explanation:
Hope this helps :D
Answer:
29 counts per minute (29 cpm)
Explanation:
The half-life of a radioactive isotope is the time needed for the activity of the sample to halve.The half-life of Francium-223 is exactly 22 minutes: this means that its activity after 22 minutes becomes exactly half of its initial value. Since the initial activity of this sample of francium-223 was 58 cpm, the activity after 22 minutes will be

Answer:
i do not know
Explanation:
im doing for education too