Elements that are good conductors of heat and electric current.
What is metals.
100
Who created the first periodic table?
Who is Mendeleev.
100
In the modern periodic table, the elements are arranged by increasing __________ number.
What is atomic.
100
The close match between Mendeleev’s predictions and the actual properties of new elements showed how useful his periodic table could be.
What is True.
100
Until 1750, scientists had identified only _____ elements.
What is 17.
200
Elements that are poor conductors of heat and electric current.
What is Nonmetals.
200
How did the first periodic table arrange the elements?
What is by mass.
200
Group 4A elements all have how many valence electrons?
What is 4.
200
Properties of elements repeat in an unpredictable way when atomic numbers are used to arrange elements into groups.
What is False.
200
________________ is a value that depends on the distribution of an element’s isotopes in nature and the masses of those isotopes.
What is atomic mass.
300
Elements with properties that fall between those of metals and nonmetals.
What is metalloids.
300
The pattern of repeating properties displayed by elements in the periodic table is known as __________.
What is periodic law
300
Elements can be classified as solids, liquids, or gases, based on their states.......
What is at room temperature.
300
On the periodic table, rows are called groups and columns are called periods.
What is False.
300
Which element is the most abundant element in Earth's crust? & Which element is the most abundant metal in Earth's crust?
What is oxygen;aluminum
400
An electron that is in the highest energy level of an atom.
What is valence electron.
400
Name the 4 categories that Antoine Lavoisier placed the elements in:
What is metals, nonmetals, gases, & Earths
400
An important property of _________________ elements is their ability to form compounds with distinctive colors.
What is transition.
400
Which of these statements is false about nonmetals? A. Nonmetals are poor conductors of heat and electric current/ B. Nonmetals that are solids tend to be malleable/ C. Many nonmetals are gases at room temperature/ D. Some nonmetals are extremely reactive and others hardly react at all.
What is B.
400
Describe the noble gases:
What is colorless, odorless, and unreactive.
500
One twelfth the mass of a carbon-12 atom.
What is atomic mass unit (amu)
500
Which two elements in Group 2A have essential biological functions?
What is magnesium & calcium.
500
Which of these statement is false about a carbon-12 atom? A. It has 6 protons and 6 neutrons/ B. It is used as a standard for comparing the masses of atoms/ C. Scientists assigned a mass of 6 atomic mass units to the carbon-12 atom/ D. An atomic mass unit is defined as one twelfth the mass of a carbon-12 atom.
What is C.
500
List the four main pieces of information that is given for each element on the periodic table: