What was Democritus's theory?

• Matter could not be divided into smaller and smaller pieces forever

• Atomos

• Matter could be divided into smaller and smaller pieces forever

• BOOYAKASHA!!!!

What was John Daltons theory?

• All elements are composed of atoms

• Atoms of the same element are exactly alike

• Compunds are formed by the joining of two or more elements

• Atoms of different elements are different

What did JJ thompson discover

• That an atom is made of even smaller particles

• That an atom is one particle

• none of the above

• alll of the above

What was the name of JJ thompsons model??????????

• carmel pie model

• peach pudding model

• plum pudding model

• baklava model

What did ernest rutherford discover

• nothing

• that atoms have a positivley charged center

• atoms have no center

• atoms have a negativley charged center

Why are chemical equations always balanced? Select ALL that apply.

• Matter cannot be created.

• Matter cannot be destroyed.

• Matter can only be rearranged/conserved.

• Matter doesn't matter.

The right side of the equation below is called the

• products
• reactants

Which of the following lists the elements in order, from those having the fewest protons to those having the greatest number of protons?

• Li, Be, He, C, N

• N, P, As, Sb, Bi

• Cs, Rb, Po, At, Rn

• At, I, Br, Cl, F

Which elements most likely belong in the same group on the periodic table?

• R and Q

• X and Y

• Y and R

• Q and X

How many protons, neutrons, and electrons are present in an atom of hafnium, Hf, with a mass number of 178?

• 72 protons, 178 neutrons, 106 electrons

• 178 protons, 250 neutrons, 72 electrons

• 106 protons, 72 neutrons, 106 electrons

• 72 protons, 106 neutrons, 72 electrons