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The source of CO comes from incomplete combustion of fuels containing carbon.
Carbon monoxide combines irreversibly with haemoglobin in the red blood cells, reducing the ability of the red blood cells to carry oxygen. This can result in respiratory problems, brain damage or death.
When both substances are added at the same time, they will react to produce a salt, ammonia gas and water.
Slaked lime will be used up in the reaction, hence the acidity of the soil will not be reduced.
Fertilizers will be used up in the reaction. Ammonia gas produced will escape to the surroundings, so nitrogen element, which is needed by the plants for healthy growth, will not be absorbed by the plants.
The work done at the barrel is equal to the work done at the nozzle.
Word Done = Force x Distance.
The force at the barrel > the force at the nozzle, so for equal work done,
distance moved by water leaving barrel per second < distance moved by water leaving the nozzle per second.
This results in a greater speed of the water leaving the nozzle.
Alternative Answer:
Volume of water leaving the barrel per second = Volume of water leaving the nozzle per second.
The cylindrical volume = Base area x distance moved by the water.
Since base area of barrel > base area of nozzle, so for equal volumes,
distance moved by water leaving barrel per second < distance moved by water leaving nozzle per second.
This results in a greater speed of the water leaving the nozzle.
Advantages:
1. The hydrogen fuel cell produces water as the only waste products. No harmful gases are released to surroundings when it is used.
2. Hydrogen is an abundant resource, if a cost effective method can be used to extract hydrogen from water.
Disadvantages:
1. There is currently no cost effective method of storing the hydrogen gas.
2. There is currently no cost effective method of extracting hydrogen from seawater.
3. The process to obtain hydrogen, either from electrolysis of water, or from cracking of hydrocarbons, produces waste gases and use up large amount of energy.
When one end of the solid rod gains heat, the heat energy absorbed is converted to kinetic energy in the rod particles. The particles at this end of the rod vibrated more vigorously in their fixed positions. The increased vibration is passed on to the neighbouring particles, causing the neighbouring particles to also vibrate more vigorously. Hence the increased vibration of the particles is passed on from particle to particle, till the particles at the other end of the rod also vibrate more vigorously.
When the average kinetic energy of the particles in the rod increases, the temperature of the rod increases. Heat energy is hence transferred from the hotter end of the rod to the cooler end of the rod through vibration of particles.
In metals, besides particle vibration, there is also electron diffusion to transfer the heat energy. The delocalised electrons are able to move more freely, hence heat conduction in metals is faster compared to non-metals.
Sunlight reaches Earth’s atmosphere and is scattered in all directions by all the gases and particles in the air. The visible light rays of sunlight consists of the spectrum of red, orange, yellow, green, blue and indigo light rays. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. The scattered blue light high up in the atmosphere causes the sky to appear blue.
Watch the video to get a better idea!
Each oxygen atom needs to share two electrons to achieve a stable electronic structure of a noble gas.
However, one hydrogen atom can only share one electron to achieve its own stable electronic structure.
Therefore, one oxygen atom will share 2 valence electrons with 2 hydrogen atoms to form the H2O molecule.
Potassium chloride is an ionic compound. The ions in potassium chloride are held together by strong electrostatic force of attraction. A lot of energy is needed to break down these bonds, hence the high melting point.
Diamond has a giant molecular structure. It consists of a large number of carbon atoms covalently bonded to one another to form a giant tetrahedral structure. This structure is a strong and rigid structure, making diamond very hard.
Graphite has a giant molecular structure. It is made up of layers of carbon atoms covalently bonded. Each layer is made up of carbon atoms covalently bonded to one another in hexagonal rings. Each carbon atom is covalently bonded to 3 other carbon atoms, hence each carbon atom has 1 valence electron not involved in bonding. These electrons are delocalised, and can move freely within the layer to conduct electricity.