All categories

3 years ago

How many atoms are in a sample of 1.83 moles of potassium (K) atoms?

1 answer:

4 0

<span>Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

</span>1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K

You might be interested in

The theory of the origin of the universe that is most popular among space scientists suggests that our universe originated how l

Anna007 [38]

Answer:

10 - 20 million years ago

3 0

3 years ago

Find the equivalent resistance Req between terminals a and b if terminals c and d are open and again if terminals c and d are sh

adoni [48]

Answer:

351 ohm

720 ohm

Explanation:

When c and d are open:

Terminals c and d are open.. If you redraw the circuit as below, you can see that the two resistors in the first column are in parallel as, they are connected together at both pairs of terminals (due to the short).

Hence, we have a pair of parallel resistors:

Req1 = (R1*R2)/ (R1 + R2) = 360*540/(360+540) = 216 ohms

Req2 = (R3*R4)/ (R3 + R4) = 180*540/(180+540) = 135 ohms

Now these two sets are in series with another Hence,

Req = Req1 + Req2 = 216 + 135 = 351 ohms

Answer: 351 ohms

When c and d are shorted:

The current will flow through the least resistant path naturally from resistors R3 and R1 or R4.

Both of these resistor lie in a single path placing the resistors in series to one another, hence

Req = R3 + R1 = 180 + 540 = 720 ohms

Answer:720 ohms

7 0

3 years ago

A student sits at rest on a piano stool that can rotate without friction. The moment of inertia of the student-stool system is 4

irina [24]

Here We can use principle of angular momentum conservation

Here as we know boy + projected mass system has no external torque

Since there is no torque so we can say the angular momentum is conserved

$mvL = (I + mL^2)\omega$

now we know that

m = 2 kg

v = 2.5 m/s

L = 0.35 m

I = 4.5 kg-m^2

now plug in all values in above equation

$2\times 2.5 \times 0.35 = (4.5 + (2\times 0.35^2))\omega$

$1.75 = [4.5 + 0.245]\omega$

$1.75 = 4.745\omega$

$\omega = 0.37 rad/s$

so the final angular speed will be 0.37 rad/s

4 0

3 years ago

Urgent need help 100 points

Sati [7]

Answer: The velocity with which the sand throw is 24.2 m/s.

Explanation:

Explanation:

acceleration due to gravity, a = 3.9 m/s2

height, h = 75 m

final velocity, v = 0

Let the initial velocity at the time of throw is u.

Use third equation of motion

The velocity with which the sand throw is 24.2 m/s.

7 0

2 years ago

A resistor with R = 300 Ω and an inductor are connected in series across an ac source that has voltage amplitude 500 V . The rat

max2010maxim [7]

Answer:

Explanation:

Rate of dissipation of energy at resistor

= I² R = 296

current I² = 296/R = 296 / 300

I = 0.9933 A.

Impedence Z = V / I = 500 / .9933

= 503 ohm.

B ) Let it be V

voltage across resistance = 300 x .9933 = 298 v

Now 500² = 298² + V²

V = 401 v

C) Power factor = R / Z

=300 / 503

= 0.596

6 0

3 years ago