An atom of sodium has an atomic mass of 23 and an atomic number of 11. The atom contains

A chemical reaction involves the rearrangement of atoms to form new molecules. During a chemical reaction, however, atoms are neither created nor destroyed. Which of the following is true about the atoms involved in a chemical reaction? A.

Which of the following is true about chemical bonds? A. Chemical bonds can form when valence electrons are transferred or shared between atoms. B. Chemical bonds do not involve transferring or sharing of valence electrons between atoms. C.

Which half reation equation represents the reduction of an iron (II) ion? Fe+2->Fe+3 + e - Fe+2 + 2e - - >Fe Fe+3 + e - - > Fe+2 Fe->Fe+2 + 2e-

The charge of an electron is A. - 2. B. 0. C. - 1. D. + 1.

What causes a lunar eclipse? Why doesn't a lunar eclipse occur during each full moon?

Students measuring the mass of a rock record 6.759 g, 6.786 g, 6.812 g, and 6.779 g. Which other measurement of the block's mass would be most precise? A. 6.702 g B. 6.781 g C. 6.605 g D. 6.858 g

What two elements make up dihydrogen monoxide?

What did scientists observe using the earliest microscopes

Which statement describes the redox reaction that occurs when an object is electroplated? A. It is spontaneous and requires an electric current. B. It is spontaneous and produces an electric current. C.

How are electromagnetic different than all other waves