Answer: Br2 I2 N2 Cl2 H2 O2 F2 (7 elements)
Explanation:
How to remeber this: Hal-NOH or BrINCIHOF
halogens Nitrogen, Oxygen, and Hydrogen.
Answer:
If anything but H2O were found, it would be evidence of a chemical change. Therefore, 4 is the only viable evidence that it was a physical change of H2O liquid to H2O gas.
Answer:
Growth of weeds and grasses
Explanation:
The part of the garden, probably left to rest by the Gardner, would start experiencing a legion of invasive plants. Giant weeds and grasses could be seen, and brambles and tree seedlings could also sneak in.
Some Gardeners would recommend the use of herbicides to restore order to an abandoned garden even though certain scientists are of the opinion that chemicals may not offer a sound solution to the problem.
To balance the the chemical reaction, the number of moles
per element is balance is both side of the reaction and also the charge in both
sides of the reation. to balnce the reaction:
S2O3 2- + Cu 2+ ---> S4O6 2- + Cu+
2S2O3 2- + Cu 2+ ---> S4O6 2- + Cu+ + e