Answer:
All are true of the movement of Earth's atmosphere except :
d. Warm air is less dense than cool air so it tends to sink towards the Earth's Surface.
Explanation:
- When gases heat up, their volume increases and density decrease.
- A decrease in density causes a substance to become lighter.
- Thus, when air warms up due to heat from the sun its density decreases and it gets lighter.
- So, it will move up.
- The Cooler air in turn is denser and heavier so it will sink towards the Earth's surface.
- Hence, the statement d , which states that 'warm air is less dense than cool air so in tends to sink towards the Earth's Surface' is FALSE.
Answer : A metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.
Explanation :
The group 16 element are oxygen, sulfur, selenium, tellurium and polonium.
The general electronic configuration of group 16 elements is, 
As we now that there are total 6 electrons in p sub-shell. So, a metal in group 16 can become a chemically stable ion by gaining 2 electrons.
Hence, a metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.
Answer:
explanation below
Explanation:
A) Biodiversity is simply known as the number and variety of organisms found in a definite environment or region. Scientists have devised several ways of measuring biodiversity and the methods to be used depend on the type of organisms they are to count.
Canopy fogging – one of the ways of measuring biodiversity, has remained an effective way of obtaining details about the biodiversity of insects. It involves the act of spraying low dose of insecticides on a tree top, and when the insects fall from the trees, they are being collected on a large screen, that looks like a funnel.
Transact sampling is another way of measuring biodiversity and this time, with a transact line. The transact line is usually a measuring tape or rope that has been marked at set intervals.
b) Ecosystem stability is the ability of the ecosystem to maintain its steady state, even after it has experienced stress or disturbances. The biodiversity of an environment makes huge impact on the ecosystem stability in that particular area. It has been known that certain areas that have high levels of species and genetic diversity, are more likely going to an ecosystem that is complex, with varying food webs and biotic interactions. The increase in this complexity makes it more likely that the ecosystem of that area will rightly move back to a stable state whenever disturbances are experienced.
There are evaluated scientific evidence that shows that reduced biodiversity affects the transmission of communicable disease in agricultural crops, animals and humans. Loss of biodiversity usually increases susceptibility to diseases in plants and humans.
Answer:
Polar bears consume ringed seals (which are tertiary consumers) as well as fish like trout, salmon, and cod (which are secondary consumers).
Explanation:
The correct answers are:
• that dark matter exists
The existence of dark matter (invisible matter) is generally accepted and it is believed that this matter is about 85% of the total matter in the universe and it is composed of undiscovered subatomic particles.
• that invisible matter must be influencing the rotation of galaxies
Dark matter is crucial for explaining why galaxies can spin without tearing themselves apart.
