1. by what are isotopes identified? a. mass numbers b. atomic masses c. atomic mass units d. average atomic masses
and
2. uranium atoms each have 92 protons. how many protons does each u-238 atom have? a.92 b.146 c.238 d.330
and
3. chlorine atoms each have 17 protons. how many neutrons does each cl-37 atom have? a.17 b.20 c.37 d.54

Which of the following changes to a pipe would increase the conductance by a factor of 12? 1.quadrupling the length and tripling the radius.2.reducing the length by a factor of and doubling the radius.3.tripling the length and reducing the radius by a factor of .4.reducing the length but a factor of and doubling the radius.

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

Determine the change in width a, height b, thickness t when a plate is subjected to the uniform distributed load and is made of material having modulus of elasticity e=230 gpa and poisson's ratio ν=1/3. given : a=400 mm and b= 300 mm also the uniformly distributed load in downward y direction of plate is 2 mn/m and in the positive x direction is 3 mn/m and t=20 mm