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
garri49 [273]
3 years ago
9

Which of the following statements are correct? 1. Electrons and protons have identical masses but opposite charges. 2. Most of a

n atom's mass is concentrated in a small, positively charged, nucleus. 3. Atoms have equal numbers of protons and neutrons. a 1 only b 2 only c 3 only d 1 and 2 only
Physics
1 answer:
lisabon 2012 [21]3 years ago
7 0

Answer:

b 2 only

Explanation:

The mass of an electron is 9.10938356 × 10⁻³¹ kilograms while the mass of a proton is 1.6726219 × 10⁻²⁷ kilograms. It can be seen that a proton is heavier than an electron.

Atoms do not always have the same number of neutrons and protons. For, example ¹³C has 6 protons and 7 neutrons.

Atoms do have most of the mass concentrated at the center called the nucleus. The nucleus has protons and neutrons. As protons have positive charge and neutrons have no charge the nucleus has a positive charge.

You might be interested in
A car goes from rest to a velocity of 108 km/h north in 10s what is the car's acceleration in m/s2
fomenos

initial velocity of the car given as

v_i = 0

final velocity is given as

v_f = 108 km/h

as we know that

1 km/h = 0.277 m/s

now we can convert final speed into m/s

v_f = 108 * 0.277 = 30 m/s

now acceleration is rate of change in velocity

a = \frac{v_f - v_i}{t}

a = \frac{30 - 0}{10}

a = 3 m/s^2

so the acceleration of the car is 3 m/s^2

7 0
3 years ago
Does a neutrally charged object even have a charge?
Roman55 [17]
“Charged objects have an imbalance of charge - either more negative electrons than positive protons or vice versa. And neutral objects have a balance of charge - equal numbers of protons and electrons. The principle stated earlier for atoms can be applied to objects. Objects with more electrons than protons are charged negatively; objects with fewer electrons than protons are charged positively.

In this discussion of electrically charged versus electrically neutral objects, the neutron has been neglected. Neutrons, being electrically neutral play no role in this unit. Their presence (or absence) will have no direct bearing upon whether an object is charged or uncharged. Their role in the atom is merely to provide stability to the nucleus.”

Hope this helps a bit.


!! (Credits to The Psychics Classroom) !!
8 0
3 years ago
Read 2 more answers
99 percent of the earth's atmosphere by mass is made up of only elements. These elements are
Alja [10]
99% of the earth´s atmosphere by mass is made up of only these elements: Nitrogen and oxygen.

Answer: B) Nitrogen and oxygen.
8 0
3 years ago
Read 2 more answers
when light falls obliquely, there is a change in direction as it moves from one medium to another but when it falls perpendicula
exis [7]

Answer:

wait in comments....................

3 0
2 years ago
"A steel rotating-beam test specimen has an ultimate strength of 120 kpsi. Estimate the life of the specimen if it is tested at
MrRissso [65]

Answer:

life (N) of the specimen is 117000  cycles

Explanation:

given data

ultimate strength Su = 120 kpsi

stress amplitude σa = 70 kpsi

solution

we first calculate the endurance limit of specimen Se i.e

Se = 0.5× Su   .............1

Se = 0.5 × 120

Se = 60 kpsi

and we know strength of friction f  = 0.82

and we take endurance limit Se is = 60 kpsi

so here coefficient value (a) will be

a = \frac{(f\times Su)^2}{Se}     ......................1  

put here value and we get

a = \frac{(0.82\times 120)^2}{60}  

a = 161.4  kpsi

so coefficient value (b) will be

b = -\frac{1}{3}log\frac{(f\times Su)}{Se}  

b =  -\frac{1}{3}log\frac{(0.82\times 120)}{60}  

b = −0.0716

so here number of cycle N will be  

N =  (\frac{ \sigma a}{a})^{1/b}

put here value  and we get

N =  (\frac{ 70}{161.4})^{1/-0.0716}

N = 117000

so life (N) of the specimen is 117000  cycles

7 0
3 years ago
Other questions:
  • Two forces, F? 1 and F? 2, act at a point, as shown in the picture. (Figure 1) F? 1 has a magnitude of 9.20 N and is directed at
    13·1 answer
  • A centripetal force of 5.0 newtons is applied to a rubber stopper moving at a constant speed in a horizontal circle. If the same
    12·1 answer
  • Which molecule will form a solution with a very low pH?
    14·1 answer
  • An unlit match is held near (not touching) a Bunsen flame. The match doesn't get hot enough to light because
    12·1 answer
  • A book is on the table. If the weight of the book is 25 newtons, what is the magnitude and direction of the normal force?
    15·2 answers
  • For a series circuit what is the terminal voltage of a battery or power supply equal to in terms of the potential difference or
    6·1 answer
  • PLEASE HELP What is it called when the moon passes through the penumbra of Earth’s shadow?(1 point)
    8·1 answer
  • What are indicative acts? FORENSICS
    9·1 answer
  • Guys please help this is due in a few hours and i’m panicking
    13·2 answers
  • Throw two balls from the same height at the same time at an initial speed of 20 m/s. One is thrown vertically down, while the ot
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!