What is Chemicals: Definition and 80 Discussions

A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances, chemical compounds, or alloys. Chemical elements may or may not be included in the definition, depending on expert viewpoint.Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt (sodium chloride) and refined sugar (sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical.
Chemical substances exist as solids, liquids, gases, or plasma, and may change between these phases of matter with changes in temperature or pressure and time. Chemical substances may be combined or converted to others by means of chemical reactions.
Forms of energy, such as light and heat, are not matter, and are thus not "substances" in this regard.

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  1. N

    Can I mix these 3 chemicals together?

    Can I mix these 3 chemicals together?? I'm not a chemist so don't laugh at my lack of knowledge: I want to mix pure Benzene, Toluene and Cyclohexane into a single Cuvette. Is this alright? I'm not going to produce any harmful gases or weapons of mass destruction? Thanks.
  2. M

    Medical Herbs vs Chemicals: Which is Better for Treating Illness?

    The other night I had two friends at the house for a gathering. One is an herbalist and the other is some sort of doctor, I'm not sure of his specific job title. However that is not important. These two began to bicker about medical techniques. In your opinion are herbs a better way to treat...
  3. S

    Unknown Organic Chemicals Distinction

    Homework Statement Use a flow chart to distinguish between: 1-hexene, cyclohexanol, 1-bromobutane, 1-propanol, 2-hexene, 1-hexyne, 2-bromopentane, 3-methyl-3-hexanol, 3-bromo-3-methylhexane by using a positive and negative test by adding other compoundsHomework Equations N/AThe Attempt at a...
  4. B

    Chemicals for rocket fuel and superchemicals?

    I want to get a little into rocketry and i want to know what are the best chemical mixes for solid and liquid state rockets? also i wanted to know if there are such things as super chemicals. I am not sure if i made that up or not or it just a different word but, what i mean are chemicals that...
  5. Simfish

    Can the Concept of Humidity Be Applied to Non-H20 Molecules?

    So we define humidity as.. "Relative humidity is defined as the amount of water vapor in a sample of air compared to the maximum amount of water vapor the air can hold at any specific temperature in a form of 0 to 100%" But these definitions of humidity are overly specific to Earth's...
  6. wolram

    Can Chemicals Cut Through Hardened Steel?

    I have a bet that no chemical can cut through hardened steel like in the movies, will i loose?
  7. ~christina~

    Clothes and chemicals don't mix

    [SOLVED] Clothes and chemicals don't mix After taking analytical this summer I notice I have many holes in my jeans... I spilled some Zimmermann-Reinhardt reagent on my jeans and I spilled it on my pocket of my jeans. I do know that it contains H2SO4 but I notice that everytime I was the...
  8. J

    The Skin's Natural Protection Against Caustic Chemicals

    I didn't know where to put this since it pertains to both chemistry and biology so i put it here. One time i accedently spilt 31.45% concentrated HCl on my skin and didn't notice it right away but then i saw this fuming drop on my skin and i immediately washed it off, it never tingled, burned...
  9. M

    Washing Non-Polar Soluble Chemicals with Water

    I was reading about washing non polar soluble chemicals with a polar solvent like water. How exactly is that done? If you add water to the non polar solvent containing the chemical to wash away all the water soluble chemicals how would you separate the water from the non polar? Would you have to...
  10. M

    Isolating Chemicals: Steps & Tips

    I want to learn how to isolate chemicals from substances. For example let's say I have a pile of powder which consists of about 5 different chemicals. The chemical I want to isolate is highly soluble in water. Let's say one of the other chemicals isn't soluble in water but highly soluble in...
  11. P

    How to mix parafin wax with chemicals

    I'm looking for a way to make a color flame candle . Are there any chemicals I can mix into paraffin wax to achieve these properties? The chemicals I'm looking for would be chemicals that don't cost very much and won't make the wax toxic when I'm burning it .
  12. M

    What chemicals are in generic 2 cycle motor oil?

    Does anyone have a list of the specific chemicals that are in off the shelf generic 2 cycle oils? Much appriciation if someone can give me an accurate list. Willing to compensate for an accurate list of chemicals and their chemical formulas.
  13. Evo

    News Ozone-Friendly Chemicals Lead to Warming

    How can we let things like this happen? "Cool your home, warm the planet. When more than two dozen countries undertook in 1989 to fix the ozone hole over Antarctica, they began replacing chloroflourocarbons in refrigerators, air conditioners and hair spray. But they had little idea that...
  14. P

    Chemicals that induce thirst in humans?

    Which chemicals induce thirst or make the neurons that are responsible for the brain to feel thirsty work without the 'normal' reasons (body genuinely needing water) for thirst. My guesses from experience: MSG Mass produced muffins (they probably have a chemical that induce this type of...
  15. W

    Where exactly do you get the chemicals to do your own experiments?

    A kid I've talked to on the internet's able to do his own chemistry experiments at his house, but where did he get the materials? I've lost touch with him as I've only talked to him a few times, so could you guys help me out here a bit? And tell me some safety precautions if you decide to...
  16. S

    Light emitting chemicals and electromagnetic fields.

    I am stumped, and googled out. I am interested in knowing whether or not anyone knows of a chemical in liquid form, that will glow or emit light when it is excited by electrons, or more specifically an electromagnetic field. If I am generating an electromagnetic field and want to be able...
  17. A

    Chemistry coursework, identifying unknown chemicals

    i have to do the plan of my chemistry coursework by monday... im having trouble with where to start..i have to identify 6 unknown chemicals. I am given a list with 8 chemicals that contains the name of 6 unknowns that i have and 2 extras. im thinking of starting with a litmus paper test...
  18. W

    Predicting Boiling Points of Chemicals: Is There a Theory?

    Hi, does anybody know how to predict the boiling points of chemicals? Is there is a generally accepted theory or model to explain Tb? Thanks.
  19. T

    Chemicals in foods that produce high

    Chemicals in foods that produce "high" This is a strange question i suppose...but I've wondered about it for a while- When I combine certain foods or candy + certain drinks + ephedrine I get a feeling (a type of "high") that is so extreme I nearly pass out. I am not into drugs and I only...
  20. G

    Pool Chemicals: A Dangerous Combination?

    I saw an article in Saturday's edition of the Kennebec Journal about an Augusta woman who mixed pool chemicals (calcium hypochlorite) with water in a bucket in the sink and it caused burns to her face and neck. It pays to read directions but it wouldn't hurt to hand out safety alerts where pools...
  21. N

    Making Snow with Non-Water Chemicals: A Guide

    Can you make snow out of other chemicals besides water?
  22. S

    How many chemicals are people made from?

    How many different molecules are people made from? Are there lots of new molecules to be discovered and if so,how is this known?
  23. J

    Buy Chemicals Online: Where to Find the Cheapest Prices

    Can individuals purchase chemicals online/anywhere or is it illegal? If it is legal, I would like to know the cheapest place to purchase them online.
  24. DocToxyn

    Where Can I Find Affordable Chemicals for Etching Steel?

    I'm looking to get the following: concentrated hydrochloric and nitric acid and powdered asphaltum. The book I'm getting this from suggests hardware stores or pool chemical dealers, but its dated back to the 1970's, so I'm not sure of the current availability outside of a commercial chemical...
  25. T

    Why do plants have certain chemicals?

    There are a whole bunch of plants on this planet which produce an array of chemicals. I'm sure there are chemicals in the plants which had developped as a result of natural selection; some of them are used to help the plant survive certain conditions/predators. But I'm sure there are a lot of...
  26. Saint

    Aphrodisiac normally consists of what chemicals?

    aphrodisiac normally consists of what chemicals ? how it works ?
  27. Math Is Hard

    Termite Tenting: Chemicals, Timelines, & Refrigerator Safety

    They're coming to termite tent my apt. building Wednesday A.M. What the heck are those chemicals they use for this anyway? Anyone know? I think they will finish Thurs. afternoon and I'll be able start airing out the place Thursday night and move back in Friday evening. Anyone been through this...
  28. K

    Where Can I Find Affordable Bulk Chemicals for Scientific Research?

    By "bulk chemical" i mean I need a pound of calcium carbide. anyone know where to get it? If i get it under its laymans headng, as in the stuff used for hobbying, its kind of expensive, esp for a large quantity. I assume this is markup. Thanks.
  29. W

    Exploring Alternatives to Nuclear Energy: Generating Energy from Chemicals

    Is it possible to generate energy from chemicals in a way that would be economical, and safer compared to nuclear energy, such as the removal of electrons, etc?
  30. Tsu

    Marketing Ploys: 'All Natural - No Chemicals' - A False Claim?

    Doesn't it just crack you up when a company will advertise their products touting "ALL NATURAL - NO CHEMIALS!" To me, this just flies in the face of reason. Let's see - Foxglove is all natural but it can kill you! And show me a flower that is NOT made of chemicals and I'll show you empty...
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