Answer:
C. Fe: 24 electrons
Explanation:
From the analogy given, the atom with a charge of +2 is Fe having 24 electrons.
To calculate the charges on an atom;
Number of charges = Number of protons - Number of electrons.
O: 10 electrons: 8 protons = 8 - 10 = -2
N: 10 electrons; 7 protons = 7 - 10 = -3
Cl: 18 electrons; 17 protons = 17 - 18 = -1
So;
Fe: 24 electrons and 26 protons = 26 -24 = +2
Therefore, the solution is Fe
Answer:
140 beats per minute
Explanation:
You have to multiply the ratio 14 beats/6 seconds by 10 because 6 seconds times 10 to get 1 minute. The answer you get is 140 beats/60 seconds.
Answer:
Speed of the ambulance is 32.7 metres per second.
Explanation:
Let the actual frequency of the siren be .
Frequency observed by me when ambulance is approaching = 540 Hz
Frequency observed by me when ambulance is moving away = 446 Hz
Let be the speed of sound and be the speed of ambulance.Then according to Doppler effect:
When source is moving towards observer,frequency observed is given as
= 540 Hz
When source is moving away from observer,frequency observed is given as
= 446 Hz
Taking and solving the above two equations by eliminating ,
we get
Answer: B
Explanation:
The equation to find momentum is velocity*mass. Without velocity, there would be no momentum. Therefore the object CAN NOT be at rest.