Groups
Elements in group 2 of the periodic table are the
Alkaline Earth Metals
The atomic mass of an element is ____ of that element.
the number of protons plus the number of neutrons of an atom
In which of the states of matter is nitrogen at room temperature?
Gas
What is the name of the element whose symbol is S?
Sulfur
When magnesium and fluorine react, what type of bond is formed?
Ionic
Elements from which group all have two electrons in their outer energy levels?
Alkaline Earth Metals
The atomic number is the number of ____ of an atom of that element.
protons in the nucleus
This group of elements are malleable, ductile, and are good conductors of heat and electricity.
Metals
What is the chemical symbol for carbon?
C
_____ are atoms of the same element that have different numbers of neutrons.
Isotopes
To which group do the elements Fe, Co, and Ni belong?
Transition Metals
The mass of an electron is ____
negligible (so small it doesn't matter)
Most metallic elements have all of these properties except
A. ductile
B. malleable
C. brittle
D. high melting point
C. Brittle
different mass, same atomic number describes an
isotope
____ are different molecular structures of the same element.
Allotropes
Which group of elements in the periodic table contains the noble gases?
group 18
The atomic number of manganese is 25; its mass number is 55. How many neutrons does an atom of manganese have?
30
As you move from left to right on the periodic table, metallic properties
decrease
Which element is present in all organic compounds?
Carbon
Which model of the atom reflects the unpredictable motion of the electron?
electron cloud
Which group contains the most active nonmetals?
group 17
How many electrons do atoms of the alkali metals have in their outer energy levels?
1
Elements such as silicon and germanium that conduct an electric current under certain conditions are called
semiconductors
Which group of elements on the periodic table is unreactive?
Group 18 (noble gases)
All elements that have more than 92 protons can be classified as
transuranium elements