1.5g of a sample containing chromium (Cr) gave 0.220g of Cr2O3 when suitably oxidized. What is the approximate percentage by mass? The answer is 10 but I don't know how to get the answer.

well in order to answer this question you have to provide more information < 3

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

answer: e.   sour taste

explanation: acids are those substances which dissociates in water to give ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. acids are sour in taste. example: hcl

bases are those substances which dissociates in water to give ions or accepts ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. bases are bitter in taste. bases are slippery in nature.

it is the most commonly accepted one