19. a material with a shape that remains unchanged when it is moved from one container to another is a(

A material with a shape that remains unchanged when it is moved from one container to another is a solid.
Liquids don't have a shape - they can assume the shape of any container they are put into. Whereas solids don't change the shape they already have even though they are placed in various other containers.

Iwould go with i'm not positive because i'm dumb that

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer