Atomic Structure/Bonding/Periodicity

Which of the following diagrams BEST illustrates bonding of nitrogen?

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Which of the following statements about covalent compounds are TRUE?

• They are mainly solids

• They usually have low melting and boiling points

• They are usually insoluble in water

• They contain only ions

Which of the elements forms a chloride which is ionic in nature?

• I

• II

• III

• IV

The arrangements of electrons in atoms X and Y are 2,8,5 and 2,8,6 respectively. Which of the following options represents X and Y?

• A

• B

• C

• D

Which of the following describes the formation of a metallic bond? A metallic bond is formed when

• anions are held together by negative electrons

• metal atoms are held together by molecular forces

• cations are held together by a sea of mobile electrons

• positive metal ions are held together by a sea of anions

Which of the following elements does NOT form simple ions by gaining or losing electrons?

• Carbon

• Copper

• Calcium

• Chlorine

Which of the following elements has 7 electrons in its outer shell?

• Hydrogen

• Oxygen

• Nitrogen

• Chlorine

An atom has 20 electrons. When it ionizes, it has the same electronic configuration as

• neon

• argon

• sodium

• calcium

Which of the following statements BEST describes the difference between an atom and an ion?

• An atom is electrically neutral but an ion is positively charged

• An atom is electrically neutral but an ion is negatively charged

• An atom contains equal numbers of protons and electrons whereas an ion contains more electrons than protons

• An atom contains equal numbers of protons and electrons whereas an ion contains unequal numbers of protons and neutrons

Which of the following features are true about the arrangement of electrons, protons and neutrons in an atom?

• Protons and neutrons are found in the nucleus

• Electrons can be found anywhere outside the nucleus

• The number of protons is the same as the number of electrons