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Nature of Matter-Jes
Basic Matter
Question | Answer |
---|---|
What is the first job of a biologist? | To understand the chemistry of life |
What is the basic unit of matter? | The atom |
Define an atom. | It is the smallest particle that maintains the properties of its element |
What are the subatomic particles that make up the atom. | Protons, neutrons and electrons |
What is the mass and charge on a proton; where is it located? | positively charged; located in the nucleus Mass of 1 |
What is the mass and charge on a neutron; where is it located? | No charge; located in the nucleus; Mass of 1 |
What is the mass and charge on a electron; where is it located | negative charge; constant motion in the space surrounding the nucleus 1/1840 mass of proton |
Where is the nucleus located and what holds it together? | At the center of the atom and a strong nuclear force holds protons and neutrons |
Why do electrons remain outside the nucleus? | Because of the energy of their motion. |
What is an element and how many are known? | A pure substance that consists entirely of one type of atom; over 100 known |
About how many elements are found in living organisms? | 24 |
What does an element's atomic number represent? | The number of protons |
What are isotopes? | Atoms of the same element that differ in the number of neutrons. |
How are isotopes represented? | By their name + their mass number |
How is atomic mass calculated? | By the weighted average of the mases of an element's isotopes |
Do isotopes of an element have the same chemical properties? | Yes because they habe the same number of electrons. |
Since radioactive isotopes nuclei are unstable and break down at a constant, how can this be used? | This allows geologists to determine age of rocks and fossils and can be used to follow movement "tracers" in organisms to diagnose problems. |
What is a chemical compound? | substance formed by chemical combination of 2 or more elements in definite proportion. |
Are physical and chemical properties of elements the same as their elements? | No Example Hydrogen and oxygen to make water. Sodium and chlorine to make table salt |
What are the two main types of chemical bonds? | Ionic and Covalent bonds |
How is an ionic bond formed? | When one or more electrons are transfered from one atom to another, thus creating positive and negative ions which have a strong attraction for each other and form crystals structures |
How is a covalent bond formed? | Some electrons prefer to share electrons so that electrons travel in orbits of both atoms,and can make single, double or triple bonds |
What is a molecule? | A molecule is smallest unit of most compounds like H covalent bond with O |
What makes Van der Waals Forces? | In sharing electrons in covalent bonds, some atoms have stronger attraction for the electrons creating a partial + or - charge on one part of molecule and this can cause intermolecular forces of attraction between the molecules |
What organism uses this force to climb smooth vertical surfaces? | The geckos |