smallest piece of an element
What is an atom?
particle with a positive charge
What is a proton?
number in square in periodic table that tells you the number of protons in the center of an atom
What is atomic number?
material that can be pounded into shapes
What is malleable?
material that can be pulled, formed into long wire
What is ductile?
the central core of an atom
What is a nucleus?
particle with a neutral charge
What is a neutron?
number that tells you the average mass of one atom of an element
What is atomic mass?
physical characteristics such as hardness, shininess, malleability and ductility are physical characteristics of __________________
What are metals?
a mixture of metals
What is an alloy?
particles in the center of an atom
What are protons and neutrons?
a particle with a negative charge
What is an electron?
elements in a vertical column of the periodic table is a __________ of elements
What is a group?
these elements are
-found in group 1
-the most reactive metals
-never found uncombined in nature
What are alkali metals?
these elements are:
-found in group 2
-not as reactive as elements in group 1, but still very reactive
-never found uncombined in nature
What are alkaline earth metals?
particle in the space around the center of an atom
What is an electron?
elements in horizontal rows in a periodic table is a __________ of elements
What is a period?
these are elements are:
-found in group 3-12
-form a bridge between very reactive metals and less reactive elements
-very similar to each other
What are transition metals?
elements placed under the rest of the elements on the table so it doesn't get very wide
What are lanthanides and actinides?
What is a valence electron?
more reactive elements are toward this side of the periodic table
What is the left?
elements with properties/characteristics that are the opposite of metals
What are nonmetals?
elements in group 17 that have 7 valence electrons
What are halogens?