THANK YO If an individual proton has mass 1.007825 amu and an individual neutron has mass 1.008665 amu, and the observed atomic mass of gadolinium-157 is 156.92396 amu, what's its mass defect? Question 19 options: A) 1.38269 amu B) 1.35833 amu C) –1.35833 amu D) –1.38269 amu

1.38269 amu

Explanation:

Gadolinium-157 has 64 protons and 93 neutrons. Recall that mass defect his the difference between the calculated mass and the actual mass of the atom. This difference in calculated mass and actual mass exists because some mass is converted to the binding energy of the nucleus.

Mass of 64 protons= 64 × 1.007825 = 64.5008 amu

Mass of 93 neutrons= 93 × 1.008665 = 93.805845 amu

Mass of neutrons and protons= 64.5008 + 93.805845 = 158.306645 amu

Mass defect= 158.306645 - 156.92396 = 1.38269 amu

Therefore, mass's defect of gadolinium-157 is 1.38269 amu

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.

the answer is c.the valence of the atoms combine .