Answer: C
Explanation:
According to Neils Bohr, atoms contain electrons which are arranged in energy levels. The energy levels proceed from the lowest to the highest. When energy is supplied to an atom,it moves from lower to higher energy levels. The higher energy level is known as the excited state. Excited states are short lived and atoms quickly return to ground state with emission of the absorbed energy in the form of visible light. This visible light must have one of the seven colours observed in the visible spectrum; Red, orange, yellow, indigo, blue, green, violet. Energy required for this excitation is supplied by heating the substance in a flame.
Answer:
Alkali metal hydroxides can be used to test the identity of metals in certain salts. The colour of the precipitate will help identify the metal : Calcium hydroxide is soluble; no precipitate is formed.
Answer:
a) 2.173
b) 20ml
c) 3.87
d) 4.35
e) 8.8
f) 12.45
Explanation:
chech the attachment for explanationns
Less dense than the liquid
Answer:
New cells arise from existing cells.
Explanation:
According to the cell theory, "all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells"(Lumen Learning).
Cells are the basic unit of life. Some organisms consists of only one cell while other organisms have many cells and are called multicellular organisms.
In multicellular organisms, new cells are formed by the division of preexisting cells.
