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
ryzh [129]
3 years ago
8

How many neutrons does element X have if it’s atomic number is 28 and it’s mass number is 81?

Physics
2 answers:
Sedaia [141]3 years ago
8 0

The answer is 53,hope this help

Sauron [17]3 years ago
3 0

Answer:

53

Explanation:

M-A=N

Mass-Atomic #= Neutrons

81-28= 53

You might be interested in
An automobile engine has an efficiency of 19.0%. If it produces 23.0 kJ of mechanical work per second, the heat rejected per sec
creativ13 [48]

Answer:

(e) 98,1 KJ

Explanation:

The engine produces 19%; it means, it rejects 81% of energy. ⇒ 81/19=4.26 times.

The engine produces 23 kJ; it means it rejects 23 * 4.26 = 98.05263 kJ

5 0
3 years ago
How do you find average velocity
monitta

Answer:

find the sum of the inital and final velocitys and divide by 2 to find the average

4 0
3 years ago
Help please :pensive:
tino4ka555 [31]

Answer:

0m/s²

Explanation:

Given parameters:

Initial velocity of the boat = 8m/s

Final velocity  = 8m/s

Time taken  = 4s

Unknown:

Acceleration of the boat = ?

Solution:

Acceleration is the rate of change of velocity with time.

It is mathematically expressed as;

        A = \frac{v - u}{t}

A is the acceleration

v is the final velocity

u is the initial velocity

t is the time taken

    Insert the parameters and solve;

  A = \frac{8-8}{4}   = 0m/s²

6 0
3 years ago
A substance freezes at 25 degree celcius and boils at450 degree celcius at what temperature will the subsancehave a definate sha
Bad White [126]

Answer:

solid

Explanation:

I really don't know

4 0
3 years ago
Read 2 more answers
The texture of obsidian is best described as glassy.Why does obsidian contain few or no mineral grains? by the way I put it unde
Brrunno [24]

hi, so the material that would normally form mineral crystals does not have time to form a crystalline structure because of very rapid cooling after volcanically erupting into the air or onto the surface. Obsidian is a volcanic glass.

4 0
3 years ago
Other questions:
  • A horizontal pull A pulls two wagons over a horizontal frictionless floor, the first wagon is 500N, the second is 2000 N. The te
    12·1 answer
  • How are the types of energy in the electromagnetic spectrum defined? (Points : 3)
    6·2 answers
  • The dimensions of a room are 16.40 m long, 4.5 m wide and 3.26 m high. What is the volume of the room in cubic meters? Express y
    5·1 answer
  • What happens when you push a spring? How is this different than pulling it? (Hooke’s Law)
    14·2 answers
  • Suppose no stars more massive than about 2 solar masses had ever formed. Would life as we know it have been able to develop
    9·1 answer
  • In the vertical jump, an athlete starts from crouch and jumps upward to reach as high as possible. Even the best athletes spend
    14·1 answer
  • What are the two <br>factors in which weight of object depends?​
    9·2 answers
  • What is the twisted ladder shape of the DNA called?
    10·2 answers
  • . En 1/2 hora, un ciclista recorrió 20 kilómetros. ¿Cuál fue el promedio de velocidad del ciclista? a. 10 km / h b. 60 km c. 40
    6·1 answer
  • Can someone help<br> pls !
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!