How do you find the average atomic mass

Which is true of transition metals when moving from left to right on the periodic table? the d sublevels are not filled across the period. the cation radii become larger across the period. atomic radii increase slightly and then start to decrease. atomic radii decrease slightly and then start to increase. o

1) these are barrel shaped microtubules in most animal cells, that organize the spindles during cell division

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as