Answer:
Climate change has been described as one of the biggest problems faced by humankind. Carbon dioxide is is the primary driver of global warming. Prof Joanna Haigh from Imperial College London explains why this gas has played a crucial role in shaping the Earth's climate.
Carbon dioxide (CO2) has been present in the atmosphere since the Earth condensed from a ball of hot gases following its formation from the explosion of a huge star about five billion years ago.
At that time the atmosphere was mainly composed of nitrogen, CO2 and water vapour, which seeped through cracks in the solid surface. A very similar composition emerges from volcanic eruptions today.
As the planet cooled further some of the water vapour condensed out to form oceans and they dissolved a portion of the CO2 but it was still present in the atmosphere in large amounts.
Classification systems previously were having very different goals than modern classification systems. If we look at old eras, scientists like Aristotle and Theophrastus tried to classify organisms on the basis of apparent characteristics, habitat and simple other traits.
Old classification systems had alot of errors and flaws. For example they classified fish and whale in one group because they lived in water, now we know fish is amphibian while whale is mammal.
So we can say that the goal o earlier classification system were just to make groups of organisms on the basis of External features.
Goal of modern classification system:
Modern classification approach was started by Linnaeus. It focuses more on biological delimitation and evolutionary histories than mere external characteristics. It organizes organisms in groups in such a way that grouping reflects their evolutionary relatedness. It is not just specie level but also focuses on sub-specie and population level classification.
Thus modern goal is better in many terms and is more reliable than old classification goals.
Hope it helps!
Mastication is the process by which food is crushed and ground by teeth. It increases the surface area of foods to allow a more efficient break down by enzymes.
Answer:
Group 17 Melting point 113.7°C, 236.7°F, 386.9 K
Period 5 Boiling point 184.4°C, 363.9°F, 457.6 K
Block p Density (g cm−3) 4.933
Atomic number 53 Relative atomic mass 126.904
State at 20°C Solid Key isotopes 127I
Electron configuration [Kr] 4d105s25p5 CAS number 7553-56-2
Explanation:
