Question

1. all of the following statements about different elements are true except: a) krypton is one of the noble gases. b) sulfur is considered a metalloid. c) barium is an alkaline earth metal. d) iodine is a halogen. e) manganese is a transition metal. 21) metalloids are located where on the periodic table? a) right side b) zig - zag diagonal line c) left side d) middle e) none of the above 22) which of the following statements about ions is incorrect? a) anions are formed when an atom gains electrons. b) cations are formed when an atom loses electrons. c) cations are positive ions and anions are negative ions. d) cations are formed when an atom gains protons. e) all statements are correct. 23) how many electrons are in br -? a) 7 b) 4 c) 34 d) 36 e) none of the above 24) what is the charge on the barium ion? a) 1 - b) 2+ c) 2 - d) 1+ e) none of the above 25) what is the charge on the cesium ion? a) 1+ b) 1 - c) 2 - d) 2+ e) none of the above 26) the nucleus of an atom consists mainly of a) protons and neutrons. b) neutrons and electrons. c) protons, neutrons, and electrons d) protons and electrons. e) none of the above

Explanation:

• Question 20: Krypton is a noble - gas. Sulfur is a non - metal, not a metalloid. Barium is an alkaline earth metal, not an alkaline earth metal. Iodine is a halogen and manganese is a transition metal. So the incorrect statements are B, C.
• Question 21: Metalloids are located along the zig - zag diagonal line on the periodic table.
• Question 22: Cations are formed when an atom loses electrons, not gains protons. Anions are formed when an atom gains electrons. Cations are positive and anions are negative. So the incorrect statement is D.
• Question 23: Bromine (Br) has an atomic number of 35. Br⁻ has gained one electron, so it has 36 electrons.
• Question 24: Barium (Ba) is in Group 2 of the periodic table and loses 2 electrons to form a Ba²⁺ ion, so the charge is 2+.
• Question 25: Cesium (Cs) is in Group 1 of the periodic table and loses 1 electron to form a Cs⁺ ion, so the charge is 1+.
• Question 26: The nucleus of an atom consists mainly of protons and neutrons. Electrons are in the electron - cloud outside the nucleus.

Answer:

1. B, C
2. B
3. D
4. D
5. B
6. A
7. A