Chapter 4 Elements and the Periodic Table
What is the smallest particle of an element?
Negatively charged particles that are lost,gained, or shared in chemical reactions are known as?
Positively charged particles in the atom's nucleus are known as?
The central core of an atom containing protons and neutrons is the?
A particle that has no electrical charge and the mass of one amu is?
What two particles are located in the nucleus?
Protons and Neutrons
The number of protons in an atom is the element's?
Atoms of the same element that have different numbers of neutrons are called?
Mass number is what
the sum of the protons and neutrons in the nucleus of an atom
Atomic mass increases in what direction?
from left to right across the periodic table
An element's properties can be predicted from its
location on the periodic table
Who created the first periodic table?
Horizontal rows in the periodic table are called
Vertical columns in the periodic table are called
A representation of an element usually consisting of one or two letters is known as what?
What are four properties of metals?
As you move from left to right across the periodic table, reactivity tends to increase or decrease?
The most reactive group of metals in the periodic table are what?
What two rows are placed at the very bottom of the periodic table?
lanthanides and actinides
How are synthetic elements made?
What are the properties of nonmetals?
poor conductors of electric current & heat, dull, and brittle
What is a diatomic molecule?
a molecule that consists of two atoms
Group 17 elements tend to gain or share one electron when they react with other elements; they are known as?
Group 18 elements are unreactive and known as what?
Between the metals and nonmetals in the periodic table are?
The atomic nuclei of unstable isotopes release fast-moving particles and energy in what process?
How did Becquerel discover radioactive decay?
On accident while studying a mineral containing uranium
Radioactive decay produces three types of particles. What are they?
alpha, beta, gamma
How are radioactive isotopes used?
tracers, industrial processes, and diagnosing and treating disease
How are radioactive isotopes used to treat some forms of cancer?
target cancer cells and destroy them