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Descrição
FlashCards por Nicholas Haddad, atualizado more than 1 year ago
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Criado por Nicholas Haddad
aproximadamente 8 anos atrás
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| Questão | Responda |
| Describe an atom. Explain the parts of an atom. | An atom is the smallest unit of an element that still retains its chemical properties. An atom has a nucleus which contains protons that are positively charged and neutrons that have no charge. Surrounding the nucleus in shells/orbits of differing energy levels are electrons, which carry a negative charge. An isotope is an atom of a certain element that has a different number of neutrons. All atoms have the same number of protons as they do electrons. The stability of the outer electron shell is what makes an atom more or less reactive. |
| Describe the relationships between atoms, elements, molecules and compounds. | Atoms are the smallest unit of an element that still retains its chemical properties. A molecule is made up of 2 or more atoms of the same element. An example of a molecule is an O2 molecule, which contains 2 oxygen atoms. A compound contains 2 or more atoms of different elements. Water, or H2O, is a compound, consisting of 2 hydrogen atoms and one oxygen atom. Together, these 4 things help to make up our bodies and the many things that exist. Elements can combine to create compounds, of which many materials on Earth are made of. Atoms are the smallest, then elements and molecules. |
| Describe the parts of a chemical formula. Identify the number of atoms, elements, molecules and compounds. | A chemical formula consists of reactants and products on different sides. During a chemical equation, both sides must have the same number of atoms for each element, as matter is neither created nor destroyed. |
| Identify Products and Reactants | The reactants are the materials going into the reaction, or the starting materials. The products are the end result(s) of the reaction, or what comes out. |
| What is an ion? | An ion is an atom or molecule that has acquired a positive or negative charge by gaining or losing electron(s). In ionic bonds, two oppositely charged ions bond to each other, creating a stable molecule. An example of an ionic bond is NaCl, or Sodium Chloride. Sodium donates it's 1 electron in its outer shell to chlorine, which has 7 in its outer shell. Without 8 in the outer shell, they are unstable, so this bond makes both atoms stable, as sodium donates one, becoming Na+, and chlorine accepting one, becoming Cl-. |
| What is a covalent bond? | A covalent bond is a bond where two or more molecules share electrons to satisfy their outer shells. An example of a covalent bond is in water. The 2 hydrogens and 1 oxygen share electrons so that each of their outer shells are full. However, the electrons aren't shared equally, with the oxygen on top. This is called a polar covalent bond. One in which the electrons are shared equally is called a non-polar covalent bond. |
| What is a hydrogen bond? | Hydrogen bonds are bonds between a slightly positive H atom and a slightly negative atom. These bonds are much weaker than covalent bonds. An example is water, as H is slightly positive and the O's are slightly negative. This bond keeps water molecules together. |
| Describe pH. | Ionization is the process by which a non-ionic compound becomes ions. A very small number of water molecules ionizes, but it is very important to our cells and bodies. When it does, it splits into H+ and OH-. The concentration of these ions in a substance is called pH. Those with more H+ than OH- are said to be acidic, while those with more OH- than H+ are said to be basic/alkaline. If an organism has the same amount of H+ and OH- ions, it is neutral. The pH scale goes from 0 to 14, where 0 is very acidic, 14 is very basic and 7 is neutral. It is tenfold, meaning that a pH of 3 has 10 times more H+ than a pH of 4. Certain pH's are necessary for our bodies to function. |
| What is an organic molecule? Which 6 elements are most common in living things? | An organic molecule is a molecule that contains carbon, and usually hydrogen or oxygen atoms as well. The 6 most abundant elements in living things are Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus and Sulfur (CHNOPS). |
| Why is carbon bonding unique and favorable? | Carbon bonding is unique because a carbon atom has 4 electrons in its outer shell, which allows for easy bonding (a full shell has 8, so 4 leaves some room for bonding). It can also bond to itself (4+4=8) and other molecules up to 3 times (single, double and triple bonding). |
| What are the 4 organic macromolecules? What are they made of (monomers) and elements? What are their functions? Be able to identify examples of each. | |
| Explain how dehydration synthesis/hydrolysis relates to the creation of organic macromolecules. | Carbohydrates, Lipids and Proteins all form using dehydration synthesis, the process by which a molecule of water is created/taken out of two molecules so that they can bond/combine. These same macromolecules are broken down using hydrolysis, where a water molecule is added back into two molecules so that they can split. Without these processes, our bodies would be unable to build or break down molecules that are necessary for structure and function. |
| Explain the similarities and differences between DNA and RNA. | DNA contains the sugar deoxyribose, while RNA contains ribose. Both are made of nucleotides, units with a 5-carbon sugar, a nitrogen base and a phosphate group. DNA's nitrogen bases are Adenine, Thymine, Guanine and Cytosine. RNA's nitrogen bases are Adenine, Uracil, Guanine and Cytosine. RNA is single-stranded, while DNA is double-stranded. Adenine and Guanine are purines, and Cytosine, Thymine and Uracil are pyrimidines. Both acids contain and carry genetic information, as well as the tools for evolution. |
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