The first answer choice is correct: SF6 is a compound: it is a substance composed of more than one atom from different elements (sulfur and fluorine).
The second answer choice is incorrect: while SF6 is indeed a compound that contains seven atoms, those atoms are not identical since one is a sulfur atom and six are fluoride atoms.
The third answer choice is incorrect: SF6 is not an element because it can be separated chemically into simpler substances that are elements. All the atoms comprising an element must have the same number of protons (the same atomic number); sulfur and fluorine have different atomic numbers. There is no single nucleus in SF6; the S and six F atoms each has their own nucleus.
The fourth answer choice is incorrect; SF6 contains no carbon atom, and so wouldn’t meet a central criterion for an organic compound. Moreover, the formula SF6 indicates that the sulfur atom is not bonded to any other atom apart from fluorine atoms, and there are no bonding electrons left on the S. There is no plausible reason to think that a molecule with such weak intermolecular attractions as SF6 would form long chains of S atoms. Indeed, in standard conditions, SF6 is a gas.
Geology and astronomy are two types of earth science. Geology is the study of rocks and minerals and astronomy is the study of space.
Answer:
Activation energy, in chemistry, the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo a chemical transformation or physical transport.
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.