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3 years ago

How many neutrons does an element have if its atomic number is 45 and its mass number is 161

2 answers:

5 0

Here is the formula that you need to know for this problem:
Number of proton (atomic number) + Number of neutrons = Mass number

So,

45 + Number of Neutrons = 161

Number of neutrons = 161 - 45

Number of Neutrons = 116

Salsk061 [2.6K]3 years ago

4 0

Proton and electron same
proton and the atomic number is same
So mass (-) atomic number
which is 161-45= 116
answer is 116 :)

You might be interested in

If 20 beats are produced within one second, which of the following frequencies could possibly be held by two sound waves traveli

NeTakaya

Answer:

D. 22 Hz and 42 Hz

Explanation:

When two waves with different frequency travelling in the same medium meet each other, they produce an interference pattern called beat.
The frequency of the beat produced is equivalent to the difference between the individual frequencies of the two waves involved.
Therefore; in this case since the frequency of the beat is 20 Hz, that is from 20 beats per second.
We need to find a pair from the choices whose frequency difference is 20 Hz.
This happens to be choice D. 22 Hz and 42 Hz, that is 42 Hz - 22 Hz = 20 Hz

8 0

3 years ago

Read 2 more answers

ALL OF MY POINTS FOR THIS!

scoray [572]

Newton's 2nd law of motion:

   Force = (mass) x (acceleration)

   = (1,127 kg) x (6 m/s² forward)

   = (1,127 x 6) newtons forward

   = 6,762 newtons forward
______________________________

   Momentum = (mass) x (speed)

   =   (69 kg) x (6 m/s)

   = 414 kg-m/s

3 0

3 years ago

Q9 A physics book slides off a horizontal tabletop with a speed of 1.10 m/s. It strikes the floor in 0.350s. ignore air resistan

Rama09 [41]

Answer:

(a) 0.613 m

(b) 0.385 m

v = 3.68 m/s², θ = 72.6° below the horizontal

Explanation:

(a) Take down to be positive.

Given in the y direction:

v₀ = 0 m/s

a = 10 m/s²

t = 0.350 s

Find: Δy

Δy = v₀ t + ½ at²

Δy = (0 m/s) (0.350 s) + ½ (10 m/s²) (0.350 s)²

Δy = 0.613 m

(b) Given in the x direction:

v₀ = 1.10 m/s

a = 0 m/s²

t = 0.350 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (1.10 m/s) (0.350 s) + ½ (0 m/s²) (0.350 s)²

Δx = 0.385 m

vₓ = aₓt + v₀ₓ

vₓ = (0 m/s²) (0.350 s) + 1.10 m/s

vₓ = 1.10 m/s

vᵧ = aᵧt + v₀ᵧ

vᵧ = (10 m/s²) (0.350 s) + 0 m/s

vᵧ = 3.50 m/s

The magnitude is:

v² = vₓ² + vᵧ²

v = 3.68 m/s²

The direction is:

θ = atan(vᵧ / vₓ)

θ = 72.6° below the horizontal

3 0

2 years ago

How long was a 60 W light bulb turned on if it used a total of 580 J of energy?

icang [17]

Here's the tool you need. You can't answer the question without this:

   "1 watt"
means
   "1 joule of energy, generated, used, or moved, every second".

So 60 watts = 60 joules per second

   Total energy generated,
      used, or moved = (power) x (time).

   580 joules = (60 watts) x (time)

Divide each side
by (60 watts): Time = (580 joules) / (60 joules/sec)

   = (9 and 2/3) seconds .

7 0

3 years ago

Find the equivalent resistance of this

frosja888 [35]

Answer:

Re=160ohm

Explanation:

Step#1

Rt=R1+R2 ( because both are in series)

Rt=(100+220 ) ohm

Rt=320 ohm

Step#2

Rt and R3 are parallel so,

Re= (Rt× R3) ÷ (Rt+R3)

Re= (320×320)÷( 320+320)

Re = 102,400÷ 640

Re=160ohm

7 0

3 years ago