Explain in terms of particle behavior why smoke particles cause the detector alarm to sound
Smoke detectors are of many types but they rely on the principle of diffusion of smoke. Diffusion is the movement of particles from a region of high concentration to a region of lower concentration. Smoke particles move in what is known as Brownian motion.
<span>1) 0.2M ferric nitrate is added gradually to 1M sodium hydroxide. In result, a red precipitate appears. The precipitate is ferric hydroxide.
2) </span><span>0.2M potassium chromate is added gradually to 0.05M lead acetate. in result, a yellow precipitate appears. The precipitate is called potassium acetate.
The common between the two is that the colors originated from one of the reactants. </span>
1.0×10^−15/4.2×10^−7=<span>2.3809524e-23 Hoped I helped!</span>
D = m / V
It even gives you the density of gold in the problem. Major hint. Once you know the volume (using V = m / D) then you can calculate the height (thickness) from the equation...
V = L x W x H
Volume = Length x Width x Height
start by converting 200.0 mg into grams
1000 mg = 1 g
200. mg x (1 g / 10^3 mg) = 0.200 g
V = m / D
V = 0.200 g / (19.32 g/cm^3)
V = 0.01035 cm^3
Convert 2.4 ft and 1 ft to cm
2.4 ft x (12 in / 1 ft) x (2.54 cm / 1 in) = 73.15 cm
1 ft = 30.48 cm
Compute the height (thickness)
V = LxWxH
H = V / LW = 0.01035 cm^3 / 73.15 cm / 30.48 cm
H = 4.64 x 10^-6 cm
Convert to nanometers
4.64 x 10^-6 cm x (1 m / 100 cm) x (10^9 nm / 1 m) = 46.4 nm
Knowing the atomic radius of gold, I might have asked my students for the minimum number of gold atoms in this thickness of gold. This would assume that the gold atoms are all in a row. This would give the minimum number of gold atoms.
Atomic radius gold = 174 pm
Diameter = 348 pm
46.4 nm x (1 m / 10^9 nm) x (10^12 pm / 1 m) x (1 Au atom / 248 pm) = 133 atoms of gold
Solid-When a solid is heated the particles gain energy and start to vibrate faster and faster. Initially the structure is gradually weakened which has the effect of expanding the solid. Further heating provides more energy until the particles start to break free of the structure. Although the particles are still loosely connected they are able to move around. At this point the solid is melting to form a liquid.
Liquid-As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles of gas in the liquid. At this point the liquid is boiling and turning to gas. The particles in the gas are the same as they were in the liquid they just have more energy. At normal atmospheric pressure all materials have a specific temperature at which boiling occurs. This is called the "boiling point" or boiling temperature.
Description of Phase Change Term for Phase Change Heat Movement During Phase Change
Solid to liquid Melting Heat goes into the solid as it melts.
Liquid to solid Freezing Heat leaves the liquid as it freezes.
Liquid to gas Vaporization, which includes boiling and evaporation. Heat goes into the liquid as it vaporizes.
Gas to liquid Condensation Heat leaves the gas as it condenses.
Solid to gas Sublimation Heat goes into the solid as it sublimates.
