Answer: A thing that died a long time ago, and it's bones were preserved in the ground.
Explanation:
Because yes
Ca^2+ and I^-
Na+ and Co3^2-
Ga^3+ and ClO3
Cu^2+ and F-
NH4^- and PO4^3-
Fe2+ and (SO4)^2-
Mg2+ and NO3^-
NH4^+ and NO2^-
K^+ and (C2H3O2)^- {C2H3O2 is acetate}
Na^+ and Cr2O7^2-
Answer:
to do day-to day activities easily and make surrounding comfortable for man
Explanation:
as an example , binary numbers help to work computers ,calculators.they help us lot .
scientific methods also need to write large and small numbers in short ways .so, scientists find various patterns .
Answer:
Changes in Properties Changes in properties result when new substances form. For instance, gas production, formation of a precipitate, and a color change are all possible evidence that a chemical reaction has taken place. ... Change in Color A color change can signal that a new substance has formed.
Explanation:
