HESI CHEMISTRY QUESTIONS and answers. Graded A+

HESI CHEMISTRY QUESTIONS and answers. Graded A+ The difference between hydrochloric acid and hydrosulfuric acid is (A) that only the first is binary (B) that only the first is ternary (C) the presence of hydrogen (D) the nonmetallic elements in each - D Which of these elements is a liquid at room temperature? (A) He (B) Ag (C) Hg (D) Zn - C Which have about the same mass? (A) Protons and neutrons (B) Neutrons and electrons (C) Electrons and alpha particles (D) Neutrons and beta particles - A Which pair are isotopes? (A) Co-60 and Kr-70 B) K-40 and Ar-40 (C) O-15 and O-18 (D) N-14 and C-14 - C What would you expect to happen when electrons in an excited state fall to lower energy levels? (A) Energy is absorbed. (B) Energy is released. (C) Energy is both released and absorbed. (D) Energy remains constant. - B Aluminum (Al) has 13 protons in its nucleus. What is the number of electrons in an Al3+ ion? (A) 16 (B) 13 (C) 10 (D) 3 - C Blood with a pH of 1.3 indicates what about the blood sample? (A) It is strongly acidic. (B) It is strongly basic. (C) It is weakly acidic. (D) It is weakly basic. - A A radioactive isotope has a half-life of 20 years. How many grams of a 6-gram sample will remain after 40 years? (A) 8 (B) 6 (C) 3 (D) 1.5 - D What is true of a measurement in which a chemical weighs 0.031 g?