Question | Answer |
What is the smallest piece of matter that still retains the properties of the element? | atom |
What are atoms of the same element that have different numbers of neutrons? | isotope |
What is the smallest known particle that makes up protons and neutrons? | quark |
What are the positively charged particles in an atom called? | proton |
What is the region called that is outside of the nucleus where the electrons are found? | electron cloud |
What are the neutral particles in the nucleus of the atom called? | neutrons |
What are the negatively charged particles in an atom called? | electrons |
What is the center of the atom that contains the protons and neutrons called? | nucleus |
What is the table of elements arranged according to repeated changes in properties called? | Periodic Table |
The horizontal row in the periodic tables is called what? | period |
What is the name for the elements found in the middle part of the periodic table? These elements are in families 3-12. | transitions elements |
What is the vertical column in the periodic table called? | group or family |
What are the elements that are found to the right if the zigzag dividing line in the periodic table? | nonmetals |
What is the number on the periodic table that represents the number of protons in an atom? | atomic number |
What are the elements that have properties of both metals and nonmetals? | metalloids |
What is the number on the periodic table that is the weighted average mass of the mixture of isotopes that exists naturally for an element? | average atomic mass |
What are the elements that are found on the left side of the periodic table or left of the zigzag dividing line? | metals |
What is the sum of the number of protons plus neutron in the nucleus? | mass number |
Who is the ancient Greek who first said that all matter was made of small indivisible particles called “atomos”? | Democritus |
Who is the Father of modern atomic theory? With his experiments in the 1800s, he showed that all elements have atoms as their smallest particle. | Dalton |
Who discovered electrons with a cathode ray tube experiment in 1904? | Thompson |
Who discovered the positive nucleus at the center of atoms with a gold foil experiment in 1911? | Rutherford |
Who showed that through light spectroscopy that electrons existed in specific energy levels in 1913? | Bohr |
What is the current atomic model that has electrons not as particles in orbits, but as wave-particles in areas of probability? | Electron Cloud Model |
Who created the first periodic table based on increasing atomic mass? | Mendeleev |
Who put the periodic table in order by atomic number? | Moseley |
What are most of the synthetic elements called? | rare earth elements |
Each energy level of an atom can hold a maximum number of what? | electrons |
What are Lewis Electron Dot diagrams used to represent? | outer level electrons |
What does the chemical symbol of an element represent? | name of the element |
In what state are most elements at room temperature? | solid |
What unit is used to measure the size of an atom? | Angstrom |
How do scientists know what an atom looks like if he can’t see it in detail? | They use experiments involving indirect observations to create a model. |
What two things did Mendeleev use to arrange the periodic table? | a. He ordered them according to increasing mass. b. He grouped them according to similar properties. |
What are 2 similar properties of Na and K? | They are both soft metals that react with water. |
What makes Na and K so similar? | They both contain the same number of electrons in the outer energy level. |