Answer:
Average atomic mass = 21.38 amu.
Explanation:
Given data:
Mass of first isotope = 21 amu
Abundance of first isotope = 62%
Mass of second isotope = 22 amu
Abundance of second isotope = 38%
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (62×21)+(38×22) /100
Average atomic mass = 1302 +836 / 100
Average atomic mass = 2138 / 100
Average atomic mass = 21.38 amu.
Answer:
Until recent history,extinctions have always happened gradually and on a small scale.
Explanation:
Extinction occur when environmental factors like natural disaster,habitat fragmentation,over exploitation,global change don't favor the survival of species thus gradually leads to extinction of species.
Some times human activity becomes the major problem for extinction.More over,poor reproduction,decline in population number and genetic inbreeding also leads to extinction.
99% of all species that exist on earth become disappeared.
Evolution leas to speciation which leas to formation of new species but species become extinct when they are unable to survive against competition.
All of the above- 1, 2, and 3 These introduce variation into the chromosome or into the zygote and create cells and offspring unique from the parents.
False it is just the opposite if the gfr levels are increased it leads to reduced urine production.
Plants and animals live in interacting, interwined communities. There is a characteristic set of species in different environments. For example, certain species of trees, shrubs, ground cover, arthropods, reptiles, mammals, birds etc. live in a temperate forest environment. A completely different set of creatures live in a marsh, or a grassland or an agroecosystem. However, the relationships between these groups can be defined by the ecological role they play, the flow of energy between them and the cycling of nutrients between them. This is a fancy way of saying "everything is connected"! And if you change one part of the system, something else changes. In an ecosystem management decision, you hope you know what those consequences of your actions are!) This is important in managing agroecosystems as well.
