Chemisrty Flashcards
(47 cards)
What’s Chemistry?
Chemistry is the study of matter, its properties and its changes and transformations.
What is Matter?
Matter is anything that has mass and takes up space.
Classified according to it’s composition:
Either a pure substance or a mixture.
What are Properties?
The characteristics that make something unique.
What are Chemical Properties?
Those substances that describe how one substance reacts with others.
We can not identify a chemical reaction until the substance undergoes a chemical reaction. Whether a substance is flammable or rusts is a Chemical Property.
What is a Chemical Change?
One or more new substances are formed.
What are Alkaline Earth Metals?
- Second column on the periodic table.
- Reactive Metals that are always combined with non-metals in nature.
- Several of these elements are important mineral nutrients (such as Mg and Ca.)
What are Alkalic Metals?
- First column on the periodic table (Group 1) not including hydrogen.
- Very reactive metals, always combined with something else in nature (like in salt-sodium and chlorine.)
- Soft enough to cut with a butter knife.
What is Hydrogen?
- Belongs to its own family.
- Is diatomic (always found as h2.)
- Very reactive.
- Involved in the explosion of the Hindenburg
- As promising as an alternative fuel source for automobiles.
What are the vertical columns on the Periodic Table called?
They’re called groups and are labeled from 1-18.
What are the horizontal rows on the Periodic Table called?
They’re called periods and are labeled from 1-7.
What are Chemical Changes?
When an entirely new substance is formed.
Example: Iron and Oxygen combine to form iron oxide (rust).
What is a Chemical Property?
How elements and compounds react.
We can’t identify a Chemical Reaction until a substance undergoes a Chemical Reaction.
Whether a substance is flammable or rusts is a chemical property.
Example: Hydrogen is a very reactive element, He is not.
What is a Physical Change?
They change one of the Physical Properties but not the actual substance.
Example: Melting Ice
What are Physical Properties? And what are they?
Things are can be observed.
- Color
- Smell
- Luster (shine)
- Density
- State
- Solubility (ability to dissolve)
What are Compounds?
Pure substance that contains two or more elements in a fixed proportion.
The smallest part of a compound is called a molecule. A molecule consists of 2 or more atoms chemically bonded together.
What is an Element?
Pure substances that cannot be broken down into simpler substances.
What is Homogeneous?
Solution.
One substance dissolving into another.
What is Heterogeneous?
Mechanical Mixtures
The individual parts or components of the mixture remains intact and visible.
What are Noble Gases?
Elements in Group 18.
- VERY un-reactive, monotonic gases.
- Used in lighted “neon” signs.
- Used in blimps to fix the Hindenburg problem.
They are un-reactive because they have full valence shells.
What are Halogens?
Elements in Group 17.
- Very reactive, volatile, diatomic, nonmetals.
- Always found combined with other elements in nature.
- Used as disinfectants and to strengthen teeth,
What is the Oxygen Family or Chalcogens?
Elements in Group 16. - Oxygen is necessary for respiration. - Many things that stink contain sulfur. Example: 1. Rotten Eggs 2. Garlic 3. Skunks
What is the Nitrogen Family?
Elements in Group 15.
- Nitrogen makes up over 3\4 of the atmosphere.
- Nitrogen and Phosphorus are both important living things.
- The red stuff on the tip of matches is Phosphorus.
What is the Carbon Family?
Elements in Group 14.
- Contains elements important to life and computers.
- Carbon is the basic for an entire branch of Chemistry (Organic Chemistry).
- Silicon and Germanium are important semiconductors.
What is the Boron Family?
Elements in Group 13.
- Do not occur elementally in nature (in compounds).
All but Aluminum.
