Inside the Atom
Everything around us is made of tiny building blocks called these.
atoms
The vertical columns of the periodic table are called these.
groups/families
This Russian scientist is famous for creating an early version of the periodic table.
Dmitri Mendeleev
Most elements on the periodic table belong to this category and are generally good conductors of heat and electricity.
metals
A substance made of only one type of atom is called this.
element
These three particles make up atoms.
protons, neutrons, and electrons
The horizontal rows of the periodic table are called these.
periods
Mendeleev intentionally left these in his periodic table for elements that hadn't been discovered yet.
gaps/empty spaces
Helium, neon, and argon belong to this famously unreactive family.
noble gases
A substance formed when two or more different elements are chemically combined is called this.
compound
The number of these particles determines which element an atom is.
protons
The modern periodic table is arranged in increasing order of this number.
atomic numbers
Unlike today's table, Mendeleev mostly arranged elements according to this property.
atomic mass/atomic weight
Lithium, sodium, and potassium belong to this highly reactive Group 1 family.
alkali metals
Two or more atoms chemically joined together form this.
molecule
Atoms of the same element can have different numbers of these particles, creating isotopes.
nuetron
Elements in the same group often behave similarly because they have the same number of these outer electrons
valence electrons
This scientist discovered that every element has a unique number of protons, helping scientists arrange the modern periodic table correctly.
Henry Moseley
Fluorine, chlorine, and bromine belong to this reactive family located just left of the noble gases.
halogens
In this type of chemical bond, atoms share electrons instead of transferring them.
covalent bond
An atom has 12 protons and 10 electrons. What is its overall charge?
+2
An unknown element is in the same group as fluorine and chlorine. Even without knowing its name, you can predict that it probably has this many valence electrons.
7
Later scientists discovered that arranging elements by this, rather than atomic mass, fixed important problems in Mendeleev's table.
atomic number
Mystery Element: I'm a nonmetal, essential to living things, found in diamonds and graphite. Who am I?
carbon
Sodium wants to lose one electron, while chlorine wants to gain one. When sodium gives its electron to chlorine, the oppositely charged particles attract. What type of bond forms?
ionic bond