Ernest Rutherford discovered that atoms were mostly:

Negatively charged

Positively charged

Electrons

Empty space

In a balanced chemical reaction, the total mass of the products always equals the

Which element in period 4 has the highest electronegativity? A) potassium B) calcium C) copper D) bromine

What is the concentration of ammonia in a solution made by dissolving 3.75 g of ammonia in 120.0 l of water?

Scientist think that many species have one common ancestor. Which answer choice best tells why scientists think this way? Group of answer choices homologous structures all of the answer choices the fossil record vestigial structures

How might you explain the difference between the pH values of the 0.01 M HCl (pH = 1.1) and the 0.01 M HC2H3O2 (pH = 3.6) ? HCl produces less H+. HCl dissociates more. HC2H3O2 produces both H + and OH-. HC2H3O2 produces more H+.

A 0.75mol calcium carbonate (CaCO3) pellet has what mass?

The pH of the acid in the stomach is 2. When a person has heartburn, the acid in their stomach is coming up the esophagus (lower throat) and burning the lining of the esophagus. Why would a person take an Alka Seltzer tablet for heartburn?

Calculate the photon energy (in joules) for the light emitted from the hydrogen atom if ninitial = 4 and nfinal = 2.

The distance from one place to another

What is the purpose of a cell membrane