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3 years ago

Wich of these is not a sign of chemical change 1 A gas is given off

Physics

1 answer:

mash [69]3 years ago

5 0

<h3>Answer:</h3>

2. The material dissolves

<h3>Explanation:</h3>

The Question tests the understanding of chemical change and whether we know the signs that show its occurrence.

First we need to know what is chemical change;

Chemical change is a type of change that involves formation of a new substance different from the original substance.

Second we need to identify the signs that indicate the occurrence of a chemical change

Chemical change in chemical reactions is characterized by various signs which include;

Production of bubbles
Color change
Formation of a precipitate
Change of odor
Change in temperature.

Therefore, in this case, the material dissolving is not a sign that chemical change has taken place.

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After Moseley's discovery in 1913, the periodic law stated that physical and chemical properties tend to repeat periodically whe

stich3 [128]

Answer:

Option B

Explanation:

The correct answer is Option B.

Before Moseley's discovery in 1913, In Mendeleev's periodic table the elements rearranged with increasing atomic mass.

Mendeleev was not able to locate hydrogen atom and late isotopes found violate Mendeleev table. The biggest drawback was that the atomic mass was not regular when moving one element to another.

But Moseley's arranged element in the periodic table with increasing atomic number.

3 0

3 years ago

You are performing an experiment that requires the highest possible energy density in the interior of a very long solenoid. Whic

Alinara [238K]

Answer:

b. increasing the number of turns per unit length on the solenoid

e. increasing the current in the solenoid

Explanation:

As we know that energy density depends on the strength of the magnetic field. The magnetic field strength depends on the no of turns of the solenoid and the current passing through it. The greater the number of turns per unit length, greater the current passing through it, more stronger the magnetic field is. As

B = μ₀nI

n = no of turns

I = current through the wire

So the right options are

b. increasing the number of turns per unit length on the solenoid

e. increasing the current in the solenoid

5 0

3 years ago

A block attached to a spring with an unknown spring constant oscillates with a period of 2.0 s. What is the period if

Zigmanuir [339]

Answer:

a) If the mass is doubled, then the period is increased by $\sqrt{2}$ . Hence, the period of the system is 2.828 seconds.

b) If the mass is halved, then the period is reduced by $\frac{\sqrt{2}}{2}$ . Hence, the period of the system is 1.414 seconds.

c) The period of the system does not depend on amplitude. Hence, the period of the system is 2 seconds.

d) If the spring constant is doubled, then the period is reduced by $\frac{\sqrt{2}}{2}$ . Hence, the period of the system is 1.414 seconds.

Explanation:

The statement is incomplete. We proceed to present the complete statement: <em>A block attached to a spring with unknown spring constant oscillates with a period of 2.00 s. What is the period if </em><em>a. </em><em>The mass is doubled? </em><em>b.</em><em> The mass is halved? </em><em>c.</em><em> The amplitude is doubled? </em><em>d.</em><em> The spring constant is doubled? </em>

We have a block-spring system, whose angular frequency ( $\omega$ ) is defined by the following formula:

$\omega = \sqrt{\frac{k}{m} }$ (1)

Where:

$k$ - Spring constant, measured in newtons per meter.

$m$ - Mass, measured in kilograms.

And the period ( $T$ ), measured in seconds, is determined by the following expression:

$T = \frac{2\pi}{\omega}$ (2)

By applying (1) in (2), we get the following formula:

$T = 2\pi\cdot \sqrt{\frac{m}{k} }$

a) If the mass is doubled, then the period is increased by $\sqrt{2}$ . Hence, the period of the system is 2.828 seconds.

b) If the mass is halved, then the period is reduced by $\frac{\sqrt{2}}{2}$ . Hence, the period of the system is 1.414 seconds.

c) The period of the system does not depend on amplitude. Hence, the period of the system is 2 seconds.

d) If the spring constant is doubled, then the period is reduced by $\frac{\sqrt{2}}{2}$ . Hence, the period of the system is 1.414 seconds.

8 0

3 years ago

2. When can you legally use your cell phone while

Juliette [100K]

Never is the correct answer

4 0

3 years ago

Read 2 more answers

Frost wedging occurs when water seeps into a crack in a rock, freezes, and causes the crack in the rock to widen.

Ilia_Sergeevich [38]

Answer:

the answer is true.

3 0

3 years ago