1. explain the change of state from solid dry ice to carbon dioxide gas. 2. the motion of the particles in dry ice and carbon dioxide gas. 3. explain how the original mass of dry ice compares with the mass of carbon dioxide gas.

1. Since the solid carbon dioxide never become liquid on melting under normal pressure. Thus through the process of sublimation, the solid carbon dioxide changes to gas

2. The molecules in dry ice, are in caged like structure just as the normal water ice but as it melts, the CO2 molecules having high affinity for gaseous state converts into a gas.

3. Dry ice is heavier than its gaseous form. Density of dry ice = 97.6 lb/cu.ft.

Density of carbon dioxide gas = 0.1144 lb/cu.ft.

With higher density and a fixed volume, mass of dry ice is higher than the CO2 gas

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =