4. The difference between an atom and and element is
a. an element is made of atoms
b. atoms are made of elements
c. atoms are held together by covalent bonds
d. none of the above
C?
6. Which of the following is NOT an organic compound?
a. ATP molecule
b. saturated fatty acid
c. monosaccharide
d. ammonia
not sure...
7. Carbohydrates and lipids have many carbon-hydrogen bonds; therefore they both
a. store energy in these bonds
b. are easily dissolved in water
c. dissolve only in vinegar
d. exist only in cells of plants
A?
8. All organic compounds contain the element
a. carbon
b. nitrogen
c. calcium
d. sodium
A?
Thanks
-MC
4. The difference between an atom and an element is that an element is made of atoms (option a). To understand this, you need to know that an atom is the smallest unit of a chemical element, while an element is a pure substance made up of one type of atom. Elements are represented by their atomic symbols on the periodic table, such as hydrogen (H) or oxygen (O).
6. The answer to this is option d. Ammonia is not an organic compound. To determine this, you need to understand that organic compounds are based on carbon atoms bonded to other carbon atoms or to other elements like hydrogen, oxygen, nitrogen, etc. The presence of carbon is essential for a compound to be considered organic. In contrast, ammonia (NH3) consists of nitrogen bonded to hydrogen atoms and does not contain carbon.
7. The correct answer is option a. Carbohydrates and lipids store energy in carbon-hydrogen bonds. This is due to the high energy content of these bonds. When broken down, these bonds release energy that can be used by living organisms. Water solubility (option b) or vinegar solubility (option c) is not directly related to the energy storage properties of these compounds. Carbohydrates and lipids are found in various organisms, not limited to plants (option d).
8. The correct answer is option a. All organic compounds contain the element carbon. This is a fundamental characteristic of organic compounds. While other elements, such as hydrogen, oxygen, nitrogen, etc., are also commonly present in organic compounds, carbon is always present. Carbon is unique in its ability to form stable bonds with many other elements, allowing for the vast diversity of organic compounds found in nature. Nitrogen (option b), calcium (option c), and sodium (option d) are not always found in organic compounds.