What is a disadvantage of hydrogen fuel cells? There are disadvantages to using hydrogen-oxygen fuel cells in cars. These include: hydrogen is in the gas state at room temperature and pressure, so it is difficult to store in the car. fuel cells and electric motors are less durable than petrol engines and diesel engines, so […]
What are general fire precautions?
What are general fire precautions? The term ‘general fire precautions’ (GFPs) is used to mean the measures in places of work to reduce the risk of fire and its spread on the premises, and include: providing arrangements for action to be taken in the event of a fire on the premises, including: the instruction and […]
Does salt increase water density?
Does salt increase water density? Density is the mass of a material per unit volume. Adding salt to the water increases the density of the solution because the salt increases the mass without changing the volume very much. When enough salt is added to the water, the saltwater solution’s density becomes higher than the egg’s, […]
What causes sodium voltage-gated channels to open?
What causes sodium voltage-gated channels to open? When a stimulus reaches the threshold at the axon hillock, an action potential is generated. An action potential relies on many protein channels. All the voltage-gated Sodium channels open when the membrane potential reaches around -55 mV and there’s a large influx of Sodium, causing a sharp rise […]
What does the bubbling indicate?
What does the bubbling indicate? When substances are put in the same container like, CaCO3 and HCl . A reaction occurs and bubbles escape the container (effervescence). These bubbles are actually gas fumes, and this shows that a new gaseous product is formed. Here, bubbling indicates our chemical reaction. What are the bubbles that you […]
What cycle does a refrigerator work on?
What cycle does a refrigerator work on? Air cycle refrigeration works on Reversed Carnot cycle and Bell Coleman cycle. Air is compressed and then heat removed, this air is then expanded to a lower temperature than before it was compressed. . Where is refrigeration used? Refrigeration has many applications, including household refrigerators, industrial freezers, cryogenics, […]
What is a piece of cosmic debris on Earth called?
What is a piece of cosmic debris on Earth called? It also contains countless asteroids and comets – the debris of the cosmic construction site that created the planets and their moons. The majority of Solar System asteroids populate the main asteroid belt, lying between the orbit of Mars and Jupiter. How much space debris […]
Why do mid-latitude cyclones finally die out?
Why do mid-latitude cyclones finally die out? All mid-latitude cyclones eventually weaken and dissipate. This can happen for a combination of the following reasons: loss of access to warm air, loss of access to moisture, occlusion of cooler/drier air around the low. Generally, the cold front moves faster than the warm front. How long do […]
What is the relationship between different trophic levels?
What is the relationship between different trophic levels? The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and […]
What are 3 adaptations that allow plants to survive on land?
What are 3 adaptations that allow plants to survive on land? Plants have evolved several adaptations to life on land, including embryo retention, a cuticle, stomata, and vascular tissue. What challenges did plants have to overcome to live on land? The life on land presents significant challenges for plants, including the potential for desiccation, mutagenic […]