Biology 1201 Exam 1 Questions with Correct Answers 2024

Biology 1201 Exam 1 Questions with Correct Answers 2024 About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? - Carbon, Hydrogen, Nitrogen, Oxygen What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons? - 6 Which of these refers to atoms with the same atomic number but different atomic masses? - Isotopes Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have? - 10 An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have? - 5 Atoms with the same number of protons but with different electrical charges _____. - Are different ions In salt, what is the nature of the bond between sodium and chlorine? - Ionic What is the result of the animated process? A bond between Na and Cl form where one electron from Na transfers to Cl - a positively charged sodium ion and a negatively charged chlorine ion An ionic bond involves _____. - an attraction between ions of opposite charge What type of bond is joining the two hydrogen atoms? - Covalent A(n) _____ refers to two or more atoms held together by covalent bonds. - molecule This atom can form up to _____ single covalent bond(s). Atom with 4 valence electrons - 4 A(n) _____ bond joins these two oxygen atoms. - A double covalent bond The brackets are indicating a(n) _____ bond. - hydrogen bond What name is given to the bond between water molecules? - hydrogen Which of these figures correctly illustrates the nature of the bonding of H2O? - What type of bond joins the carbon atom to each of the hydrogen atoms? - Single (nonpolar) covalent A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) _____. - element Which of the following subatomic particles always has a positive charge? - proton Changing the number of _____ would change an atom into an atom of a different element. - protons Hydrogen bonding is most often seen _____. - when hydrogen is covalently bonded to an electronegative atom Many of water's emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____. - are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _____. - High specific heat The smallest unit of an element that retains all of the properties of that element is: - an atom From its atomic number of 15, it is possible to predict that phosphorus always has: - 15 protons An atom with the atomic number 9 will have _______ electrons in its outermost electron shell - 7 True or False, an atom with more neutrons than the atom described in the question above will have a different valence. - False True or False, based on the atom described in the question above, the valence of that atom is 1 - False An atom with the atomic number 15 has a valence of? - 3 An acid is a substance that _____ - increases the hydrogen ion concentration of an aqueous solution A pH of 6 is how many times more acidic than a pH of 9? - 1,000 What is the arrow pointing to? - Hydrogen ion