On the periodic table, the element “K’ represents Potassium. Potassium has an atomic number of 19. It has an atomic mass of 39.098. The number of protons is equal to the atomic number, so Potassium has 19 protons. To find the number of neutrons in an element, subtract the atomic mass from the atomic number. (39-19). This means that the element K has 20 neutrons. Finally, to find the number of electrons, you just take the atomic number, and you have your number of electrons. Thus, Potassium has 19 electrons.
The tricks above work for any element on the Periodic Table, so feel free to use them! Here is a little way to remen then by:
A = P = E M - A = N
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T R L M T E
O O E A O U
M T C S M T
I O T S I R
C N R C O
S O N
# N # S
S
I really hope this helps :)
Answer:
D, positive
Explanation:
If displacement is increasing (positive) and time cant be negative. This means that the velocity is increasing.
Hope this helps.
Answer:
The power of the kettle is P = 1 watt.
Explanation:
The definition of power is:
Power equals the quotient between work and time, or:
P = w/t.
In this case, we know that the work is:
w = 1J
And the time is:
t = 1 s
Then the power will be:
P = 1J/1s = 1 J/s
Also knowing that:
1 J/s = 1 W
(w is the unit for Watt)
We can conclude that the power of the kettle is:
P = 1 W
Answer: v = 3.57×10^6 m/s; R = 4.42×10^-3m; T = 7.78×10^-9 s
Explanation:
Magnetic force(B) = 4.60×10^-3 T
Electric force(E) = 1.64×10^4 V/m
Both forces having equal magnitude ;
Magnetic force = electric force
qvB = qE
vB = E
v = (1.64×10^4) ÷ (4.60×10^-3)
v = 3.57×10^6 m/s
2.) Assume no electric field
qvB = ma
Where a = v^2 ÷ r
R = radius
a = acceleration
v = velocity
qvB = m(v^2 ÷ R)
R = (m×v) ÷ (|q|×B)
q=1.6×10^-19C
m = 9.11×10^-31kg
R = (9.11×10^-31 * 3.57×10^6) ÷ (1.6×10^-19 * 4.6×10^-3)
R = 32.5227×10^-25 ÷ 7.36×10^-22
R = 4.42×10^-3m
3.) period(T)
T = (2*pi*R) ÷ v
T = (2* 4.42×10^-3 * 3.142) ÷ (3.57×10^6)
T = (27.775×10^-3) ÷(3.57×10^6)
T = 7.78×10^-9 s