Chemical change happens when a substance combines with
another substance to form a new substance. It produces chemical reactions and
generally is not reversible except by further chemical reactions. Heat is sometimes
produced in some reactions. When chemical reactions occur, the atoms are
rearranged and an energy change happens along with it as new products are
generations. At a molecular level, chemical changes involves the making or
breaking of bonds between atoms. Some examples of chemical change are iron
rusting (iron oxide forms) and bread rising (yeast converts carbohydrates into
carbon dioxide gas).
Jupiter's atmosphere is composed predominantly of hydrogen and helium, but if you have to select any one option then we can look at the percentage of existence of these elements that would be
<span>90 percent hydrogen.
remaining 10 percent is helium
so choose Hydrogen.</span>
Answer:
(not sure) The origin of all cells observed can be traced to previous cells
Explanation:
- not all cells convert energy (?) (this I'm not sure but think so? might be wrong tho)
- not all cells have cell walls e.g. animal cells only have the cell membrane, no cell wall
- Rocks and other nonliving things are composed of cells: non living things are composed of the elements and not cells (unless they were previously alive, then they contain dead cells)
Answer:
Its right
Explanation:
The chemical formula of calcium dichromate is CaCr207
Answer : The velocity of the spaceship is, 
Solution :
As we are given that,
The speed of a spaceship = 7.58 wraps
So, 
The speed of light = 
Now put the value of speed of light in above expression, we get
So, 
The velocity of the spaceship = 
Now we have to convert the velocity of the spaceship m/s to cm/min.
Conversion :
(1 m = 100 cm)
(1 min = 60 sec)
The velocity of the spaceship = 
Therefore, the velocity of the spaceship is,
