All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down an object, what is most likely true about the surface the object is moving on? The surface is dry. The surface is rough. The surface is uneven. The surface is smooth.

Answer:the answer is a chemical change, because a gas was produced

Explanation:  yeast is a chemical

Answer:

The answer is C.

"Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions."

Explanation:

Answer:

helium

Explanation:

because there are no electrons screening it from the nucleus

Answer:

[tex]ns^2[/tex]

Explanation:

Answer:

1. 1g/ml

Explanation:

1. Density is mass divided by volume (g/mL).

10g/10mL = 1 g/mL

2. When you already know the density and the volume, you can use the density as a unit converter.

[tex]5mL*\frac{20g}{mL} = 100g[/tex]

3. It's the same with density and mass.

[tex]20g*\frac{1mL}{5g} = 4mL[/tex]

The speed of a wave can be calculated using this formula:

v = f x λ

Where:

v is the wave speed in metres per second, m/s

f is the frequency in hertz, Hz

λ (lambda) is the wavelength in metres, m

Calculation:

Given:

f = 20 Hz

λ = 100m

Using the equation:

v = f x λ

v = 20 x 100

v = 2000 m/s

Therfore, the speed of the wave is 2000 m/s

A sound wave has a wavelength of 100 m and a frequency of 20 Hz. The wave's speed is 2× 10^3 m/s.

assuming frequency = 20 Hz and wavelength = 100 m

utilized concept: v= = 20×100 = 2×10³ m/s

The frequency in physics is the quantity of waves passing a fixed location in a unit of time. It also indicates how many cycles or vibrations a body in periodic motion experiences in a given unit of time.

A sort of energy created by vibrations is sound. The molecules of the air surrounding an item vibrate as a result.. These molecules vibrate because they collide with nearby molecules, which also vibrate as a result.

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Answer:

A

Explanation:

we know that pangea was when all the continents were connected and the tectonic plates moved, causing pangea to split into multiple pieces. so north america was formed by moving tectonic plates.

i hope this helps :))

Answer: +3

Explanation: Gallium liquefies just above room temperature. Gallium is a soft solid, however it quickly becomes liquid when heated.

Answer:

c. .....................

Answer: the amount of carbon dioxide put into the atmosphere due to your consumption of fossil fuels

Your carbon footprint is the amount of carbon dioxide and other carbon compounds emitted, because of your use of fossil fuels.

Hope this helps!

Answer:

Master-at-Arms Petty Officer 2nd Class. MA2. Machine Accountant Second Class (Naval Rating) Copyright 1988-2018 AcronymFinder.com, All rights reserved.

Explanation:

Answer:

If an ion has a positive charge then it has lost an electrons.

Explanation:

So you don't "gain" anything when the ion has a positive charge. It loses an electron which means it has more protons than electrons. Thus, the ion has a positive charge. If it "gained" an electron then it would have a negative charge.

Answer:

the answer is b

Explanation:

i just did quizz

Answer:

Orange

Explanation:

I used google my b

Answer:

ORANGE

explanation:

Small pieces of sodium burn in air with often little more than an orange glow. Using larger amounts of sodium or burning it in oxygen gives a strong orange flame.

Answer:

true

Explanation:

please mark BRAINLIEST

Answer:

12

Explanation:

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\ [/tex]

From the question.

density = 0.017 g/mL

mass = 4 g

We have

[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]

We have the final answer as

Hope this helps you

Answer:

average speed around 9.1 meters/second

Explanation:

400 divided by 43.9

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

So we have

[tex]density = \frac{25}{90} = \frac{5}{18} \\ = 0.277777...[/tex]

We have the final answer as

Hope this helps you

Answer:

particle distance

solids are tightly packed

liquids are a little farther apart

and gases are very far

Answer:

the volume will expand

Explanation:

gas under pressure contracts, and expands with a lesser pressure

The volume of the hydrogen gas at 25 kPa is 8 Liters.

Explanation:

Given:

At constant temperature, 2 liters of hydrogen gas at 100kPa pressure.

To find:

The volume of the hydrogen gas at 25kPa.

Solution:

The initial pressure of the hydrogen gas =[tex]P_1=100 kPa[/tex]

The initial volume of the hydrogen gas at 100 kPa =[tex]V_1=2 L[/tex]

The final pressure of the hydrogen gas =[tex]P_2=25 kPa[/tex]

The final volume of the hydrogen gas at 25kPa = [tex]V_2=?[/tex]

Using Boyles law:

[tex]P_1V_1=P_2V_2\\100kPa\times 2 L=25 kPa\times V_2\\V_2=\frac{100 kPa\times 2L}{25 kPa}=8L[/tex]

The volume of the hydrogen gas at 25 kPa is 8 Liters.

Learn more about Boyles law here:

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Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question we have

mass = 10 × 2

We have the final answer as

Hope this helps you

Answer:

Na + CaSO4 = Na2SO4 + Ca

Explanation:

single displacement (substitution)