1.03 Chemistry

Which pure substance is made of only one kind of atom?

• an element

• an electron

• a particle

• a proton

Which of these characteristics differentiates electrons from protons and neutrons?

• They do not move.

• Electrons are larger.

• Electrons are not in a fixed position

• They are located in the nucleus.

One of the earliest atomic models was suggested by John Dalton in the early 1800s.

Which statement best reflects his thinking at the time?

• All atoms are exactly the same.

• Atoms can be divided into small parts.

• Smaller particles are found inside atoms.

• Atoms are like solid little spheres that vary based on different elements.

What determines the atomic number of an atom?

• the number of neutrons in two atoms of an element.

• the number of electrons in the outer layer of any atom.

• The number of protons in every atom of an element.

• The number of protons plus the number of neutrons in an atom.

Which of the following is a true statement about isotopes?

• The number of protons always equals the number of neutrons in all isotopes.

• The number of protons never equals the number of neutrons in an isotope.

• Different isotopes for the same element will always have the same numbers of neutrons.

• Different isotopes for the same element always have the same number of protons.

What information does the atomic mass of an element provide?

• The sum of electrons and protons in an atom.

• The difference between the number of protons and electrons.

• The number of protons and neutrons in an atom.

• The number of isotopes.

What did scientists discover when they arranged elements in order of increasing atomic mass?

• A repeating patterns of properties.

• A puzzling series of numbers.

• Alphabetical arrangement of the names of elements.

• No patters or relationships.

What is common to all elements in the same group in the periodic table?

• They have the same number of neutrons.

• They are all nonmetals.

• The have the same number of outer electrons.

• Their properties are very different.

What statement applies to the horizontal rows or periods in the periodic table?

• The properties are all the same.

• The elements have the same number of electrons.

• The properties change going across each row.

• The elements in each row combine easily.

Where are most of the nonmetals found in the periodic table?

• At the top.

• On the right side.

• In the bottom left corner.

• On the left side.