1 Which scientist first said that "elements are made up of identical atoms

which cannot be created or destroyed"?

Bohr

Democritis

Thomson

O

Dalton

Other:

A) What are the postulates of Bohr's model of an atom? (b) Show diagrammatically the electron distributions in Sodium, Lithium and Aluminium atoms

What color would you expect a weak base to turn the paper?

Sheets of cellulose make up plant

The valence electrons of the substance's atoms feel an effective nuclear charge of + 7. If the unknown substance has lower ionization energies than chlorine (Cl), what other characteristics would you expect the substance to exhibit?

An atom of which element has the greatest attraction for electrons in a chemical bond? (1) As (3) Ge (2) Ga (4) Se

Which two of the following elements would you expect to be most similar: nitrogen, chlorine, barium, fluorine, and sulfur?

Which statement best describes control rods? They are unmovable pieces. They are inert. They supply neutrons to start the nuclear chain reaction. They drive the generator

A large rift valley can be found along the east coast of Africa. It has been slowly widening over time, and it is now wide enough to contain many large lakes. Which of these best explains the slow widening of this rift valley over time? A.

How does the density of aluminum compare with the density of gold

Which of the following provided a hypothesis as to how the universe began? A) the moon collision theoryB) the big bang theoryC) the antimatter theoryD) the molten theory