Two hydrogen atoms bonded to one oxygen atom.
Because a lot of chemical compounds were used to create makeup
Physical change, seeing as how none of the chemical makeup of the water is changed.
Yes, as the water does not undergo an inherent change in its chemical makeup.
Because when the salt is dissolved, the chemical makeup of the crystal changes, making it a chemical change. However, you can evaporate the water, capture all the steam, cool the steam, and then you have the salt (original chemical makeup) and the water, making it a physical change.
Matter with a definite chemical makeup is a pure substance.
A change in temperature or pressure can affect the state of matter without altering its chemical composition. For example, melting ice to form liquid water or boiling liquid water to form steam are changes in state of matter that do not change the chemical makeup of water molecules.
Freezing is a phase transition and does not change the chemical makeup of H2O. (melting restores). Electrolysis changes the chemical structure of the water, decomposing the H2O into oxygen (O2) and hydrogen gas (H2).
A change in state of matter, such as melting, freezing, or boiling, will affect the arrangement of particles without changing the chemical composition of the substance. For example, ice melting into water involves a change in state from solid to liquid, but the chemical makeup of water remains the same (H2O).
agricultural water runoff from farmland
a spectroscope is the instrument used to determine the chemical makeup of a star.
a chemical formula
The chemical formula is N34K4Na9