Answer:
Hydrogen is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkali metals.
Explanation:
Answer:
The correct answer is option c.
Explanation:
Alkanes with higher molecular mass has higher boiling point.
Thisis because when the molar mass of the alkanes increases the the surface area increases with which van der Waals forces between the molecules of alkane also increase which increases the association of the molecules of with each other which results in increase in boiling point is observed.
The increasing order of the molar mass of the given alkanes;
So out of ethane, pentane and heptane . Heptane has highest molecular mass with higher boiling point value. Where as ethane have the lowest value of boiling point.
Answer:
Humans are modifying the world in many ways, and not all of them for the better. The changes we cause are often severe challenges to animals, plants and microbes in nature, from the introduction of pathogens or exotic invasive species to adding toxic substance or excessive nutrients, or causing climatic change. Often several changes occur at once. Nelson Hairston's lab focuses on freshwater environments, especially lakes and ponds, where some of the species present respond to environmental change with decreases in their numbers, even to the point of extinction, while others may benefit to excess, becoming so dominant that they present problems, as in the case of harmful algal blooms stimulated by nutrient enrichment or climate warming. Hairston's lab studies how individual species, food webs, and whole ecosystems are altered when the environment changes.
One way that some freshwater organisms respond to environmental change is to evolve rapidly. A marked change in the environment favors some characteristics of plants, animals and microbes over others. These character differences are often genetically based so that favored characteristics may increase in the next generation. The shorter the generation time, the faster this evolutionary change can occur. For example, tiny but abundant plankton, eaten by fish and other larger animals, can become adapted to the changed environment within a few years because their generation time is only a few days. Hairston's lab has shown that planktonic "water fleas" (Daphnia), major consumers of suspended algae in lakes, evolved to be tolerant of harmful algae within a decade of the appearance of blooms. This rapid evolution (termed "evolutionary rescue" in conservation biology) raises many intriguing questions, for all environments, not just freshwater: To what extent can we rely on species adapting rather than going extinct when their environment changes? How does the evolution of a species that plays a critical ecological role alter the interactions it has with other species, and the functioning of the entire ecosystem?
Answer is "<span>the
oxidizing agent receives electrons from the reducing agent</span><span>".
There are two types of reactants in redox reactions. One is oxidizing agent and
other is reducing agent.
Oxidizing agent is a substance which helps to oxidize other substance by
gaining electrons. This is also called as oxidizer. Due to the gaining
electrons, oxidizing agents tend to be reduced.
Reducing agent or reducer helps to reduce other substance while loosening
electrons. Hence, reducing agents tend to be oxidized.</span>
Answer:
The answer is D.
Explanation:
Volume (V) = l x w x h
V = 4 x 5 x 1.2
V = 20 x 1.2
V = 24
Density = Mass/Volume or D = M/V
D = 85,000/24
D = 3541.66666666
