Answer:
As the main sequence star glows, hydrogen in its core is converted into helium by nuclear fusion. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the core becomes unstable and contracts. The outer shell of the star, which is still mostly hydrogen, starts to expand. As it expands, it cools and glows red. The star has now reached the red giant phase. It is red because it is cooler than it was in the main sequence star stage and it is a giant because the outer shell has expanded outward. In the core of the red giant, helium fuses into carbon. All stars evolve the same way up to the red giant phase. The amount of mass a star has determines which of the following life cycle paths it will take from there.
diagram of the life cycles of low and high-mass stars
The life cycle of a low mass star (left oval) and a high mass star (right oval).
the different evolutionary paths low-mass stars (like our Sun) and high-mass stars take after the red giant phase. For low-mass stars (left hand side), after the helium has fused into carbon, the core collapses again. As the core collapses, the outer layers of the star are expelled. A planetary nebula is formed by the outer layers. The core remains as a white dwarf and eventually cools to become a black dwarf.
Explanation:
This region usually has a warm and dry climate which is interrupted by two rainy seasons. It is home to the largest animal migration in the world. What is this region?
What are the different types of aid
Answer:
Types of aid
BILATERAL AID (also known as 'tied aid') - the country receiving the aid must spend the money on goods and services from the country providing it.
MULTILATERAL AID - high-income countries donate money through organisations such as the United Nations (UN) and the World Bank
Explanation:
MARK ME
How does a quickly changing coastline affect wildlife
Answer:
It can change the wildlife's habitat and which traits are favourable.
Explanation:
Ex: If there are less islands for seals to rest on, seals that can swim for longer periods of time will reproduce more.