What are the 4 indicators that a chemical reaction has taken place? what are they

Why is sodium chloride not a mixture? Why is sodium chloride a compound?

A burning streak of light is called what

The hormone, thyroxine is secreted by the thyroid gland, and has the formula: c15h17no4i4. How many milligrams of iodine can be extracted from 15.0grams of thyroxine?

One difference between mixtures and pure subtances is that

An unknown substance has the composition of 77.87% C, 2.63% H and 55.62% O. The compound has a molar mass of 345.2 g/mole. What is the molecular formula?

How many moles of lithium are in 83 grams of lithium?

Ocean constitutes most of ___ of water a) Evaporation b) Precipitation c) Condensation d) Transpiration e) Sublimation Don't choose a random letter.

In the reaction, Zn + HCl-> ZnCl2 + H2, 25 grams Zn are reacted with 17.5 grams HCl. How many grams of H2 will be produced? A. 0.382 g of H2 B. 0.479 g of H2 C. 0.7865 g of H2 D. 0.484 g of H2

Is nail varnish soluble?

What is the periodic trend for atomic size from top and bottom in a group? From left to right in a period?