Science Quiz 1

An atom's mass number is 210 and its atomic number is 85. How many neutrons does the atom have?

125

What is an interaction that holds atoms or ions together?

A chemical bond

J. J. Thomson developed a model of the atom in which electrons are spread throughout a cloud of positive charge. Which discovery directly caused scientists to revise this model?

A small mass of positive charge was discovered in the center of the atom.

Molecules have the same or different properties as the atom before they joined?

Different

Atoms have a nucleus and that nuclei have protons in them

Earnest Rutherford

Is a period vertical or horizontal?

Horizontal

Second model of the atom- electrons-first one to add negatively charged atoms to the model

J J Thompson

Found neurons

J ames chadwick J immy neutron

First, plain, solid, atom

John dalton

Where are metals?

Left

A group of atoms held together by a chemical bond is a?

Molecule

Electron

Negative Mass: almost zero 1/2000 Outside, cloud

Neutron

Neutral Mass: 1 Nucleus

Electrons move around the nucleus at a certain distance for each path The Bohr model showed electrons surrounding the positive nucleus.

Niels Bohr

Atomic number

Number of neurons and protons combined

Protons

Positive in the nucleus, and 1

Isotopes

Same element, but different amounts of neurons

The current model of the atom shows electrons in a cloud surrounding the nucleus. How does the electron cloud model differ from the Bohr model? a. The electron cloud shows there is not empty space in an atom. b. The electron cloud shows that electrons do not have a negative charge. c. The electron cloud shows a region in which electrons are likely to be found. d. The cloud shows that all the electrons combine together to form one mass.

The electron cloud shows a region in which electrons are likely to be found.

Atomic mass

The number of neutrons in an object

Why are the shaded, zig-zag elements special?

They are metalloids

What is true about the position of all metals in the periodic table? a. They are in the first group b. They are in the bottom period. c. They are in the right most column. d. They are to the left of the zigzag line.

They are to the left of the zigzag line.

Is a a group horizontal or vertical?

Vertical

elements in the same group, have the same number of what?

number of valence electrons as you go down the chart.

atoms of elements in Groups 13-18 have the same number of valence electrons as what?

their group number.