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# Feedback Comments on Matter

by Ron Kurtus

A total of 253 comments and questions have been sent in. They are listed according to date.

## List of most recent 10 letters

### Country

Dry Ice Difference between vaporization and sublimation Kenya

Atoms Is an atom electrically neutral? Nigeria

Density Finding the density of an object Tanzania

Kinetic Theory of Matter What is a solid, liquid and gas? India

Atom as Solar System Why isn't the solar system a giant atom? USA

Density Factors How physical conditions affect density USA

Evaporation How are water molecules able to escape gravity? USA

Changing States of Matter What if matter did not change its state? Pakistan

Pressure and States of Matter Permission to use images USA

Dry Ice Using CO2 for supercritical extraction USA

Next 10

## Difference between vaporization and sublimation

Topic: Dry Ice

### Question

October 11, 2018

Differentiate between vaporization and sublimation

Kevin - Kenya

28745

Vaporization is the process that occurs when a chemical or element is converted from a liquid or a solid to a gas.

When a liquid is converted to a gas, the process is called evaporation or boiling.

When a solid is converted to a gas, the process is called sublimation. This is what happens with dry ice (frozen carbon monoxide gas).

## Is an atom electrically neutral?

Topic: Atoms

### Question

April 26, 2018

An atom is said to be electrically neutral?

melody - Nigeria

28538

It is true that an atom is electrically neutral, because it has the same number of positive (+) and negative (-) particles.

See Structure of the Atom for more information.

## Finding the density of an object

Topic: Density

### Question

April 15, 2018

1. An object with the volume of 150 cubic centimetre has a percentage of volume submerged of 60% when immerse into water. What is the density of the object?

Request!!!!!!
can I get books of supplement material which have enough questions on densities, relative densities etc

Denis - Tanzania

28520

If 60% is submerged in the water, that means that the volume of water displaced is 150 * 0.6 = 90 cc. Since the density of water is 1, the mass of 90 cc of water is 90 g.

Thus, the mass of the object is the mass of the displace water 90 g divided by 0.6 equals 150 g.

The density of the object is its mass divided by its volume or 150/90 = 1.67.

That seems to be a round-about way, but I hope it explains the subject.
Also refer to: Density of Matter and Factors Affecting Density of Matter.

Best wishes for success in your studies.

## What is a solid, liquid and gas?

Topic: Kinetic Theory of Matter

### Question

November 7, 2017

Q1. What is solid, liquids, gas

MD - India

28313

See States of Matter for an explanation.

## Why isn't the solar system a giant atom?

Topic: Atom as Solar System

### Question

October 5, 2017

I had a question about the article you wrote regarding Bohr's Model of an atom. Why do you disagree with the fact that our solar system can't be just one "giant" atom. I was hoping to get in touch with you to discuss this?

Tristan - USA

28273

Although our solar system looks like it could be a giant atom, there are a number of problems in the analogy. One it that electrons in an atom have an electrical charge, while there is nothing similar in the solar system. Also, the nucleus of an atom is made up of protons and neutrons, while the Sun is a mass of hot gases.

On the quantum scale, atomic particles are not tiny spheres but are wave packets.

Still, the similarity between the solar systems and atoms is intriguing.

## How physical conditions affect density

Topic: Density Factors

### Question

September 30, 2017

Describe how physical conditions affect density

kiprotich - USA

28267

Density is mass divided by volume. Compressing an object decreases its volume and thus increases its density.

## How are water molecules able to escape gravity?

Topic: Evaporation

### Question

September 22, 2017

How are water molecules able to escape gravity? In other words, gravity withholds H2O from leaving the surface of the earth, but that same body of water evaporates and those molecules are unaffected by gravity.

Travis - USA

28256

With water, the velocity of the molecules is not great enough to overcome their molecular attraction, and thus the material is a liquid that is kept toward the surface of the Earth. However, when H20 becomes a gas, the velocities of the molecules is much greater, such that they move about freely.

Most of those molecules velocities that are low enough to be constrained to the Earth's atmosphere. But some of the molecules of the gas or steam become accelerated due to radiation from the Sn, such that they have enough kinetic energy or velocity to escape the Earth's gravity.

Fortunately, the loss of water vapor molecules into space it very small.

## What if matter did not change its state?

Topic: Changing States of Matter

### Question

August 25, 2017

Explain that what happened if there would be no change in states of matter?

Thanks

Aamish - Pakistan

28197

If all matter stayed in its existing state or phase, ice would not melt to become water, and water could not boil into steam. Also, there would be no evaporation of water. Just these factors alone would affect living beings in a short time.

## Permission to use images

Topic: Pressure and States of Matter

### Question

August 14, 2017

I would like to use the phase diagram figures that you have on this page: http://www.school-for-champions.com/science/matter_states_pressure.htm

in an article that I am writing for the Health Physics Society. I understand that I need permission to use the figures. Is that possible that I could have permission to use your figures?

Thanks so much,

Linda - USA

28181

Yes, you have permission to use the diagrams provided you cite the source.

Best wished for success in your article. Let me know when it is published.

## Using CO2 for supercritical extraction

Topic: Dry Ice

### Question

January 29, 2017

I would like to discuss some commercial uses for Dry Ice and it's conversion to Co2 for supercritical extraction.
Please let me know if you are available to discuss.

Thank you in advance,

Gary - USA

27838

Dry ice is a convenient source of CO2. Allowing the gas from the dry ice to heat to about 31 degree C should help in the supercritical extraction process.

I hope that helps. Unfortunately, I am not an expert in this field.

Best wishes for success in your work.

Next 10

## Summary

Hopefully, this reader feedback has helped provide information about Matter issues.

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