An atom that has 84 protons and 86 neutrons undergoes a reaction. At the end of the reaction, it has 82 protons and 84 neutrons.
2 answers:
Answer: The atom undergoes alpha decay.
Explanation: An atom has 84 protons and 86 neutrons initially. When this atom undergoes a reaction the product obtained has 82 protons and 84 neutrons.
As the product obtained has 2 protons less and 2 neutrons less which means that the mass number is decreased by 4 units and atomic number is reduced by 2 units.
The atom undergoes an alpha-decay because in this decay the particle emitted is alpha particle which has an atomic number of 2 and atomic mass of 4 units.
Equation follows:
The atom which is undergoing alpha decay is Polonium (Po) and the product formed is Lead (Pb).
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Answer:
r = 9.92 mm
Explanation:
Given that,
Mass of oil drop,
It acquires 2 surplus electrons, q = +2e
Potential difference, V = 620 V
Thie potential difference is applied between the pair of horizontal metal plates the drop is in equilibrium.
We need to find the distance between the plates.
At equilibrium,
mg = qE
Since, E = V/r (r is distance between plates)
So, the distance between the plates is 9.92 mm.
Answer:
a) The average velocity is v = (60 km/h ; 0)
b) The average speed is 60 km/h
Explanation:
The velocity is a vector that has a magnitude and direction. The average speed is the distance traveled over time without taking into account the direction of the motion.
a)The average velocity is calculated as the displacement over time:
v = Δx/Δt
where
v = velocity
Δx = final position - initial position = traveled distance relative to the center of the reference system.
Δt = final time - initial time (initial time is usually = 0)
We know that the displacement is 84 km but we do not know the time. It can be calculated from the two parts of the trip.
In part 1:
v = 45 km/h = 42 km / t
t = 0.93 h
In part 2:
v = 90 km/h = 42 km / t
t = 42 km / 90 km/h
t = 0.47 h
The time of travel is 0.47 h + 0.93 h = 1.4 h
The average velocity will be:
v = 84 km / 1.4 h = 60 km/h
Expressed as a vector in a 2-dimension plane:
v = (60 km/h; 0)
b) The average speed is calculated as the distance traveled over time. Note that in this case, the distance is equal to the displacement since the direction of the motion is always in one direction. But if the direction of the second part of the trip would have been the opposite to the direction of the first part, the displacement would have been 0 (final position - initial position = 0, because final position = initial position), then, the average velocity would have been 0. In change, the average speed would have been the distance traveled (84 km, 42 km in one direction and 42 km in the other) over time.
Then:
average speed = 84 km / 1.4 h = 60 km/h
c) see attached figure.
Answer:
Explanation:
Given:
volume of air in the room,
temperature of the room,
<u>Saturation water vapor pressure at any temperature T K is given as:</u>
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putting T=298 K we have
<u>The no. of moles of water molecules that this volume of air can hold is:</u>
Using Ideal gas law,
is the maximum capacity of the given volume of air to hold the moisture.
Currently we have 80% of n, so the mass of 20% of n:
where;
M= molecular mass of water
is the mass of water that can vaporize further.