Spicy
What is unique to every element?
amount of protons
The odorless, colorless gases on the periodic table are a part of the _________________.
noble gases
What is the electron on the highest energy level called?
valence electrons
What is a row on the periodic table called?
period
Moving from left to right across a row of the periodic table, which of the following values increases by exactly one from element to element?
atomic number
The ________________ have one valence electron and are extremely reactive metals.
alkali metals
How many valence electrons does group 17 have?
7
The columns on the periodic table are called_____________.
groups
Atoms of the most reactive elements tend to have
one or seven valence electrons.
The _______________ are nonmetals that react easily with metals
halogens
An alkali metal has one valence electron, while an alkaline earth metal has
2
Which class of elements is the majority of the periodic table?
metals
Mendeleev arranged the known chemical elements in a table and intentionally did what?
left gaps that were later filled.
Among the alkali metals, the tendency to react with other substances
increases from top to bottom within the group.
Groups on the periodic table have
similar properties
The ________________ number represents the number of protons in an element.
atomic
The atomic mass of an element is
a weighted average of the masses of the element’s isotopes
Group 2A shows their reactivity when they react with what?
water
What tells us the reactivity of an element?
The amount of valence electrons
Which general statement does NOT apply to metals?
Most metals are brittle.