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4 years ago

Why are atoms arranged in periods ...???

Physics

2 answers:

Andrews [41]4 years ago

7 0

For classification, according to number of shells......

Sati [7]4 years ago

3 0

A horizontal row in the periodic table, which signifies the total number of electron shells in an element's atom. A vertical column in the periodic table, which signifies the number of valence shell electrons in an element's atom.

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A space ship to the moon covered the 216,000 km in 72 hours. What was it’s average velocity

Dahasolnce [82]

Answer:3000km/h

Explanation:

speed=distance/time

216,000km/72hrs

=3000km/h

8 0

3 years ago

Read 2 more answers

A piece of aluminum has a volume of 1.50 10-3 m3. the coefficient of volume expansion for aluminum is β = 69 ✕ 10-6 (°c)-1. the

Alex17521 [72]

Answer:

W = 3.12 J

Explanation:

Given the volume is 1.50*10^-3 m^3 and the coefficient of volume for aluminum is β = 69*10^-6 (°C)^-1. The temperature rises from 22°C to 320°C. The difference in temperature is 320 - 22 = 298°C, so ΔT = 298°C. To reiterate our known values we have:

β = 69*10^-6 (°C)^-1 V = 1.50*10^-3 m^3 ΔT = 298°C

So we can plug into the thermal expansion equation to find ΔV which is how much the volume expanded (I'll use d instead of Δ because of format):

$dV = \beta V_{0} dT\\dV = (69*10^{-6})( C)^{-1} * (1.50*10^{-3})m^{3} * (298)C\\dV = 3.0843*10^-5$

So ΔV = 3.0843*10^-5 m^3

Now we have ΔV, next we have to solve for the work done by thermal expansion. The air pressure is 1.01 * 10^5 Pa

To get work, multiply the air pressure and the volume change.

$W = P * dV = (1.01 * 10^5)Pa * (3.0843*10^{-5})m^3\\W = 3.115143J$

W = 3.12 J

Hope this helps!

4 0

3 years ago

Two identical waves are traveling toward each other in the same medium. One has a positive amplitude, meaning that its peaks onl

Olin [163]

The correct answer is Destructive Interference.

Consider the image attached below. Two waves are travelling towards each other. Blue wave always has a positive peak and the red wave always has a negative peak.

Now imagine these waves are moving through a rope. If blue waves will try to move the rope in positive direction, the red wave will pull it down, and thus the two waves will cancel the effect of each other. Thus resulting in a destructive interference.

7 0

4 years ago

Read 2 more answers

A 9.00-cm-long wire is pulled along a U-shaped conducting rail in a perpendicular magnetic field. The total resistance of the wi

m_a_m_a [10]

Answer:

0.45 N

Explanation:

Let Recall that,

The power formula is:

P = E²/R

Let A = the magnetic field

Let L = length of wire = 9.00cm = 0.09 m

let R = resistance of wire = 0.320 Ω

let v = velocity of the wire = 4 m/s

Let E = across the wire voltage

Let P = the power of the wire = 4.3 W

To Solve for E:

The formula of E = √PR

The Voltage from a magnetic field is given as,

E = vAL

We therefore Use E = E

√PR = vAL

to solve for A,

A= √PR/vL

BA= √4.3(0.32)/(4)(.09) -=0.173

A = 0.173 wA/m²

Let F be the pulling force

Let I be the current in the wire

P = I²R

I = √P/R

F = IAL

F = √P/RAL

F = √4.3/.32(0.173)(.09)

F = 0.45N

5 0

3 years ago

A small glass ball rubbed with silk gains a charge of +2.0 uc. the glass ball is placed 12 cm from a small charged rubber ball t

Gre4nikov [31]

The magnitude of the electric force between two obejcts with charge $q_1$ and $q_2$ is given by Coulomb's law:
$F= k_e \frac{q_1 q_2}{r^2}$
where
$k_e = 8.99 \cdot 10^9 N m^2 C^{-2}$ is the Coulomb's constant
and r is the distance between the two objects.

In our problem, the distance is $r=12 cm=0.12 m$ , while the magnitudes of the two charges are
$q_1 = 2.0 \mu C=2.0 \cdot 10^{-6}C$
$q_2 = 3.5 \mu C = 3.5 \cdot 10^{-6} C$
(we can neglect the sign of the second charge, since we are interested only in the magnitude of the force).

So, using the formula and the data of the problem, we find
$F=(8.99 \cdot 10^9 N m^2 C^{-2} ) \frac{(2.0 \cdot 10^{-6} C)(3.5 \cdot 10^{-6} C)}{(0.12 m)^2}=4.37 N$

4 0

3 years ago