Question

20) Which statement is NOT true about ionic bonds? A) An ionic bond occurs between positive ions and negative ions. B) Electrons are completely lost or gained in ion formation An ion has the same number of electrons as a nonionic atom of the same element. D) A salt such as NaCl is formed by an ionic reaction. 21) Which of the following would be a proposed mechanism by which stomach antacids work? A) Antacids are bases and by definition can absorb OH- out of a solution. B) Antacids are bases and by definition can absorb H+ out of a solution. C) Antacids dilute the solution, therefore lowering the pH. D) Antacids contain mostly water and so they neutralize the solution. 22) An atom's atomic mass is best described as the mass of A) protons and neutrons it contains. B) protons and electrons it contains. C) electrons in the outermost shell. D) the neutrons it contains. 23) Which of the following is/are an atom, an isotope and an ion? A) 2H or deuterium B) All of the choices are atoms, isotopes and ions. C) Hz or hydrogen gas D) H 24) Both 180 and 160 are found in nature. However, 160 is the most common. Therefore, A) 180 is the form of oxygen that provides living cells with life. B) only the common form of 160 can bond with hydrogen atoms to form H20. C) oxygen atoms can have eight or 10 neutrons. D) these are different elements. 25) An orbital is best described as A) the electron shell closest to the nucleus. B) the volume of space in which electrons are most often found. C) the original energy level of electrons in photosynthesis. D) the outermost electron shell of an atom. 26) Which element does not help makeup 95% of your body weight? A) potassium B) phosphorus C) nitrogen D) carbon

Answer 1

20. Option C is correct

An ion is formed by the loss or gain of electrons so it has either more or less number of electrons as compare to the non ionic atom of the same element.

e.g. Na has 11 electrons whereas Na⁺ ion is formed by the loss of one electron hence it has 10 electrons.

21. Option B is correct

Antacids are bases and they neutralise the acid produced in the stomach and thereby reduce the acidity.

22. Option A is correct

Atomic mass of an electron is the sum of proton and neutrons it has in the nucleus.

e.g. Atomic mass of Oxygen is 16 and each atom of oxygen has 8 protons and 8 electrons.

23. Option B is correct

H⁺ is an ion

²H or deuterium is an isotope of hydrogen 2 mass number but same atomic number i.e. 1.

H₂ is a molecule of hydrogen with two hydrogen atoms.

24. Option C is correct

The normal form of oxygen has ¹⁶O has 16 mass number with 8 neutrons in the nucleus whereas ¹⁸O is an isotope with ten neutrons in the nucleus. Both ¹⁶O and ¹⁸O are capable of bonding with hydrogen atoms to form water molecules

25. Option B is correct

an atomic orbital is a space where likelihood of finding electrons are highest.

26. Option A is correct

Almost 99 percent mass of the human body is made up of 6 elements that are - Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus and Calcium.