Which of the following is a correct pair of Alkaline earth metals?

Question

Which of the following is a correct pair of Alkaline earth metals?

Asked on March 26, 2026Chemistry

This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.

Accepted Answer · 2026-03-26T08:58:00.048Z

Here are the answers to the questions: Question 15: Which of the following is a correct pair of Alkaline earth metals? B. Magnesium and Calcium Magnesium ($\text{Mg}$) and Calcium ($\text{Ca}$) are both elements in Group 2 of the periodic table, which are known as alkaline earth metals. Question 16: Atom Z which has 10 protons and 11 neutrons gains two electrons. The ion formed is A. Z$^{2-}$ An atom with 10 protons has 10 electrons when it is neutral. If it gains two electrons, it will have 12 electrons. Since electrons carry a negative charge, gaining two electrons results in a net charge of 2-. Question 17: One application of capacitors in electronics is in C. defibrillators Capacitors are used in defibrillators to store a large amount of electrical energy and then discharge it rapidly to deliver an electrical shock to a patient's heart. Question 18: When a car engine is ignited, fuel is converted into mechanisms that move the car. Which energy conversion is involved? A. chemical energy to kinetic energy The fuel (e.g., gasoline) contains stored chemical energy. When ignited in the engine, this chemical energy is converted into thermal energy, which then drives the mechanical parts, resulting in the kinetic energy of the car's motion. Question 19: The concept of waste management involved in using refillable water bottle instead of disposable one is C. reuse Using a refillable water bottle multiple times instead of discarding it after a single use is an example of reusing an item, which is a key principle of waste management. Question 20: The life cycle of a grasshopper is incomplete metamorphosis because there is C. no pupal stage Incomplete metamorphosis, characteristic of grasshoppers, involves three stages: egg, nymph, and adult. It lacks the pupal stage found in complete metamorphosis.

Accepted Answer · 2026-03-26T08:58:00.048Z

Here are the answers to the questions: Question 15: Which of the following is a correct pair of Alkaline earth metals? B. Magnesium and Calcium Magnesium ($\text{Mg}$) and Calcium ($\text{Ca}$) are both elements in Group 2 of the periodic table, which are known as alkaline earth metals. Question 16: Atom Z which has 10 protons and 11 neutrons gains two electrons. The ion formed is A. Z$^{2-}$ An atom with 10 protons has 10 electrons when it is neutral. If it gains two electrons, it will have 12 electrons. Since electrons carry a negative charge, gaining two electrons results in a net charge of 2-. Question 17: One application of capacitors in electronics is in C. defibrillators Capacitors are used in defibrillators to store a large amount of electrical energy and then discharge it rapidly to deliver an electrical shock to a patient's heart. Question 18: When a car engine is ignited, fuel is converted into mechanisms that move the car. Which energy conversion is involved? A. chemical energy to kinetic energy The fuel (e.g., gasoline) contains stored chemical energy. When ignited in the engine, this chemical energy is converted into thermal energy, which then drives the mechanical parts, resulting in the kinetic energy of the car's motion. Question 19: The concept of waste management involved in using refillable water bottle instead of disposable one is C. reuse Using a refillable water bottle multiple times instead of discarding it after a single use is an example of reusing an item, which is a key principle of waste management. Question 20: The life cycle of a grasshopper is incomplete metamorphosis because there is C. no pupal stage Incomplete metamorphosis, characteristic of grasshoppers, involves three stages: egg, nymph, and adult. It lacks the pupal stage found in complete metamorphosis.