Dimensional analysis: a room measures 775 cm x 1400 cm x 260 cm. the density of oxygen is .001429 g/cm^3. how many kilograms of oxygen are present in the room

The  number  in Kg  of oxygen that  are present  in the room is  

403.1209  kg

calculation

mass=density x volume

density = 0.001429 g/  cm³

volume  =775 cm x 1400 cm x 260  cm =2.821 x10^8 cm³

mass  =0.001429 g/cm³  x( 2.8 x 10^8 cm³) =403120.9 grams

convert  g to Kg

that is  1 kg  = 1000 g

             ? kg    =403120.9 g

by cross   multiplication

=[(403120.9  g  x 1 kg) /1000 g]  =403.1209 kg

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

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.