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What significant contribution did William Cullen make? to enable chemists to pictorially represent

Scottish physician and chemist William Cullen introduced bonding brackets and affinity reactions, and develop chemical reaction equations.

Amixture that has two or more substances that are spread out evenly is called a. compound b. heterogeneous c. substance d. homogeneous

In which block of the periodic table is uranium (u) found? s blockd blockp blockf block

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.