1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Valentin [98]
3 years ago
12

All atoms of the element potassium have 19 protons. One of the most stable types of potassium atoms has the mass number 39. How

many neutrons make up one of these potassium atoms?
A. 19
B. 29
C. 38
D. 58
Physics
2 answers:
nydimaria [60]3 years ago
7 0
For atoms in the periodic table, the given mass number is the sum of the number of the protons (also called the atomic number) and the number of the neutrons inside its nucleus. Mathematically,
                              mass number = atomic number + number of neutrons
Substituting,
                               39 = 19  + n
                                    n = 39 - 19 = 20
Therefore, the answer is not found in the choices. 
steposvetlana [31]3 years ago
4 0

Answer:

N = 20

Explanation:

As we know that mass number is the sum of number of protons and number of neutrons present in the atom

So we will have

mass number A = 39

number of protons in the given atom (Z) = 19

so we will have

A = Z + N

39 = 19 + N

N = 20

You might be interested in
The barometer of a mountain hiker reads 930 mbars at the beginning of a hiking trip and 780 mbars at the end. Neglecting the eff
lara31 [8.8K]
We could use the change of pressure to calculate for the height climbed by the mountain hiker. The change of pressure is given by

p = rho * g * h, where p is the change of pressure, rho is the air density, g is the acceleration due to gravity, and h is the height.

Using the conversion 1 mbar = 100 Pa,

(930 - 780)(100) = (1.20)(9.80)h
15000 = 1.20*9.80*h

h = 1.28 km
6 0
3 years ago
two resistors of 20 ohm each are connected in a parallel with a battery of 10V. The total current passing through circuit is
Varvara68 [4.7K]

Answer:

1 Ampere.

Explanation:

From the question given above, the following data were obtained:

Resistor 1 (R₁) = 20 ohm

Resistor (R₂) = 20 ohm

Voltage (V) = 10 V

Current (I) =?

Next, we shall determine the equivalent resistance in the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 ohm

Resistor (R₂) = 20 ohm

Equivalent Resistance (R) =?

Since the resistors are in parallel connection, the equivalent resistance can be obtained as follow:

R = (R₁ × R₂) / (R₁ + R₂)

R = (20 × 20) / (20 + 20)

R = 400 / 40

R = 10 ohm

Finally, we shall determine the total current in the circuit. This can be obtained as illustrated below:

Voltage (V) = 10 V

Equivalent Resistance (R) = 10 ohm

Current (I) =?

V = IR

10 = I × 10

Divide both side by 10

I = 10 / 10

I = 1 Ampere

Therefore, the total current in the circuit is 1 Ampere.

3 0
2 years ago
A car is traveling north at 17.7 m/s . After 6 it’s velocity is 141 in the same direction. Find the magnitude and direction of t
Furkat [3]

By equation of motion we have   v = u + at

Where u = Initial velocity, v = final velocity, t = time taken and a = acceleration

Here v = 141 m/s, u = 17.7 m/s and t = 6 s

On substitution we will get

        141 = 17.7+ 6a

       So, a = (141-17.7)/6 = 20. 55 m/s^{2}

       Aceeleration = 20. 55 m/s^{2} along north direction.


3 0
3 years ago
Smoking and your health help!!!!
Luden [163]
Ill give you 7-12. 7.f 8.e 9. b 10.c 11.d 12. a
4 0
3 years ago
3.00 m^3 of water is at 20.0°C.
romanna [79]

Answer:

\triangle V = 0.02484m^3

Explanation:

Given

V_1 = 3.00m^3 --- initial volume

T_1 = 20.0^oC --- initial temperature

T_2 = 60.0^oC --- final temperature

\gamma = 207*10^{-6 ---  coefficient of thermal expansion:

Required

The change in volume

To do this, we make use of cubic expansivity formula

\triangle V = \gamma * V_2 * (T_2 - T_1)

So, we have:

\triangle V = 207 * 10^{-6} * 3.00 * (60.0 - 20.0)

\triangle V = 207 * 10^{-6} * 3.00 * 40.0

\triangle V = 0.02484m^3

The volume will expand by 0.02484m^3

7 0
2 years ago
Other questions:
  • What type of motion does the galaxy go through
    15·1 answer
  • How many coulombs of charge are needed to produce 29.1 mol of solid zinc?
    10·1 answer
  • What effect does an increase in temperature have on viscosity?
    5·2 answers
  • The drag coefficient of a car at the design conditions of 1 atm, 25°c, and 90 km/h is to be determined experimentally in a large
    15·1 answer
  • The voltage(or electric potential) of battery determines
    13·1 answer
  • Un paracaidista desciende desde 6 000 m de altura. Si la masa, con su equipo, es de 65 kg, ¿cuánto valdrá su energía potencial e
    15·1 answer
  • Father, I come to you worn and weary from the hard times I have walked through recently. I come to you seeking your shelter wher
    5·2 answers
  • A box of mass 5.0 kg is initially at rest. A 500 N force causes it to move horizontally through a
    7·2 answers
  • A 1kg mass is thrown to a height of 2cm. what is the potential energy​
    9·2 answers
  • Gravity and magnetism are both
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!