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3 years ago

After a match has burned which of these is not proof that a chemical reaction occurred?

2 answers:

4 0

In my estimation I would say C, I was leaning towards A, but I believe that would merely be "incomplete combustion." I hope this was semi-helpful!

Elden [556K]3 years ago

4 0

C. i say this because heat and smoke are signs that a chemical reaction is happening. for d if its gone obviously something had to have happened whether it was a chemical or physical reaction so whats left is C.

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What will happen if the two plungers are pressed together firmly? Explain your answer.

steposvetlana [31]

Answer:

This air being forced out causing the air pressure inside to be much lower than that on the outside. As higher air pressure always pushes, it keeps the two plungers together.

Hope that helps. x

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3 years ago

Joe follows the procedure below to make a compass.

Anna [14]

The answer would be C.

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3 years ago

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1. 3 main components of a circuit

siniylev [52]

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3 years ago

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An electron initially has a speed 16 km/s along the x-direction and enters an electric field of strength 27 mV/m that points in

weqwewe [10]

Answer:

a) $t=1.4\times 10^{-5}\ s$

b)S= 46.4 cm

Explanation:

Given that

Velocity = 16 Km/s

V= 16,000 m/s

E= 27 mV/m

E=0.027 V/m

d= 22.5 cm

d= 0.225 m

lets time taken by electron is t

d = V x t

0.225 = 16,000 t

$t=1.4\times 10^{-5}\ s$

We know that

F = m a = E q ------------1

Mass of electron ,m

$m=9.1\times 10^{-31}\ kg$

Charge on electron

$q=1.6\times 10^{-19}\ C$

So now by putting the values in equation 1

$a=\dfrac{E q}{m}$

$a=\dfrac{1.6\times 10^{-19}\times 0.027}{9.1\times 10^{-31}}\ m/s^2$

$a=4.74\times 10^{9}\ m/s^2$

$S= ut+\dfrac{1}{2}at^2$

Here initial velocity u= 0 m/s

$S= \dfrac{1}{2}\times 4.74\times 10^{9}\times (1.4\times 10^{-5})^2\ m$

S=0.464 m

S= 46.4 cm

S is the deflection of electron.

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4 years ago

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"Younger teens often brag about a lack of sleep, but that usually stops when they get older. Why do you think that is?"

svet-max [94.6K]

as we grow up we kinda experience some age staging so a teen got a lotta stuff going on they wanna be social active they be working on their popularity. so i guess thats it

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3 years ago