glencoe science new york science grade 8

Question: Give four characteristics of a chemical change. Answer: 1) A chemical change is a permanent and not easily irreversible. 2) A chemical change results in alteration in the composition of the molecules of the substance undergoing change and the formation of one or more new..

Question: Which of the following sentences is true about the evolutionary process? 1. There is no real 'progress' in the idea of evolution. 2. humans are unique, a totally new type of organism. 3. progress is nature's religion. 4. Evolution of life forms was rapid in..

Cell division is a method by which new cells are originated from pre-existing cells. The formation of daughter amoebae in amoeba, the development of sex cells and the growth of a young animal or plant into an adult, all involve cell multiplication. In order to multiply in number, cells un..

Chemical reactions take place and energy changes in the form of heat and light are involved A mixture does not have a fixed melting point and boiling point Examples: air, sand and salt A compound has a fixed melting point and boiling point Examples: 1.120 (water), FeS (iron sulphide) ..

>Based on this observation, Newland stated his law of octaves thus 'when elements are arranged in increasing order of their atomic mass, the eighth element resembles the first in physical and chemical properties just like the eighth note on a musical scale resembles the first note'. As a result a v..

Based on the positions in the periodic table, Mendeleev could predict the properties of some undiscovered elements. He left three blanks for elements that were not discovered at that time. He was able to predict the properties of these unknown elements more or less accurately. He named them eka-bo..

Question: SI unit of acceleration is __________. 1. 2. 3. 4. Answer: ..

Question: What will happen to the force of gravitation between two objects A and B if the distance between them is reduced to half? Answer: Let d be the distance between the two objects A and B of mass m 1 and m 2 respectively, The force between A and B when distance between them is..

Question: The structural formula of 2-butene is _________. 1. CH 3 - CH = C = CH 2 2. 3. CH 3 = CH - CH 2 - CH 3 4. CH 3 - CH = CH - CH 3 Answer: ..

Question: A stone is dropped from a cliff. Its speed after it has fallen 100 m is 1. 9.8 m/s 2. 44.2 m/s 3. 19.6 m/s 4. 98 m/s Answer: ..