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Chemistry Ava
Chemistry retake
Question | Answer |
---|---|
What is Physical Change | Change in form or appearance |
Name 4 signs of physical change | color, phase change, shape, size |
What is Chemical Change? | Change that creates new or different substances |
What is a sign of chemical change? | Heat/light or gas give off, flame, precipitate |
What is the Law of Conservation of Mass/Matter | Matter is always conserved during changes |
What is an atom | the smallest particle of matter and made up of proton, neutron and electron |
What is a proton | Positively charged subatomic particle, p* ,found in the nucleus of the atom |
What is a Neutron | neutral/no charged subatomic particle found in the nucleus of the atom |
What is Electron | Negatively charged subatomic particle orbitting the nucleus of the atom |
What is an Element | pure substance, ordered in the periodic table |
Periodic Table | way of organizing elements by their atomic number and similaritites |
What is a Group | all of the elements in the same family, or column (vertical), have the same number of valence electrons (those electrons on their outer electron shell) |
What is a Period | all of the elements in the same row (horizontal), have the same number of electron shells |
Electron Shells | where the electrons are found/held, surround the nucleus |
Valence Electrons | the electrons found on the outermost shell of an atom |
Compound | two or more DIFFERENT atoms combined together (examples: H2O & C6H1206) |
Molecule | two or more of the SAME atoms combined together )(example: H2, O2) |
Organic Compound | must contain carbon, complex compounds and found in organisms |
organic Compounds always contain______________? | carbon |
Inorganic Compound | usually do not contain carbon, simple compounds and from the Earth |
Pure substance | matter in which all of the atoms are the same, an element |
4 types of organic compounds | carbohydrates, lipids, nucleic acids, proteins |
Acid | tastes sour, feels oily, corrosive to metals and has a pH LESS THAN 7 |
Base | tastes bitter, feels slippery, dissolves hair/grease adn has a pH GREATER THAN 7 |
Neutral | neither an acid nor a base; pH of 7 |
pH | scale of 0-14 that ranks acid and bases |
what chemical changes occur during digestion? | Mouth > chemical (saliva) + physical (teeth) Stomach> chemical(HCI acid) + physical ( churning) |
Matter is never _________ or _________________. | created or destroyed |
What happens during a chemical change that does not happen during a physical change? | When chemical changes occur, a new substances is formed |
When water boils, how is the steam different from the water? | Steam is just the gaseous form or state of water. |
Phase Changes (such as water boiling) are considered physical changes. Why? | There is just a change in the state of matter, water in this case. There is no new substance form, just shape, temperature |
A nail rusting is considered a chemical change. why? | Oxidation has occurred, which is a chemical reaction; there is a change in color and it cannot be reversed. |
What is Matter | anything that has mass and takes up space (volume) |
Physical property | characteristic that can be observed |
chemical property | characteristic that cannot be observed; must be tested |
Is H2O on the periodic table? Why? | No, because its a compound and not an element |
Elements in the same___________________ have similar properties, such as amount of valence electrons | group |
The smallest type of matter is ____________ | an atom |
Matter is any material that has___________________and__________________ | mass, volume |
Why is O2 considered a molecule, and not a compound? | because it is made of the same kinds of atoms |
what kind of change is bicycle left outside rusting | chemical |
what kind of change is making a dent in a car door? | physical |
what kind of change is dissolving sugar in water? | physical |
what kind of change is milk going sour? | chemical |
what kind of change is cooking a steak? | chemical |
What kind of change is boiling water? | chemical |
what kind of change is a nail rusting? | chemical |
what kind of change is saliva breaking down crackers? | chemical |
what kind of change is tearing a piece of paper? | physical |
Electrons located on the outermost shell are called _______________________ ____________________ | valence shells |