A strong attraction between two atoms is a ____________.
chemical bond
100
The correct symbol for the element helium is H.
False, He
100
Is sharpening a pencil a physical change or a chemical chage?
A physical change.
100
Elements found of the right side of the periodic table are usually...
a-good conductors
b-good insulators
c-shiny
d-liquid at room temperature
b-good insulators
200
What is a physical property?
A characteristic that can be observed without changing the composition of a substance.
200
Iron rusting is an example of a ___________ change.
chemical
200
A periodic table is an arrangement of the elements by decreasing atomic number.
false, increasing atomic number
200
Under what conditions is an atom neutral?
When the atom has an equal number of protons and neutrons. It is neutral.
200
The state of matter that can fill any volume is...
a-solid
b-liquid
c-gas
d-plasma
c-gas
300
What is a physical change?
A change that does not affect the composition of a substance.
300
The state of matter in which atoms are held together the strongest is _____________.
solid
300
A chemical change occurs when a new substance is formed.
True
300
Atoms that give off particles and energy are ____________.
radioactive
300
What is used to treat cancer and date fossils?
a-radioactive elements
b-leptons
c-atom smasher
d-quarks
a-radioactive elements
400
What is a cheimcal property?
Characteristic that determines how a substance reacts with other substances.
400
The basic building blocks of an atom's nucleus are the ___________.
quarks
400
The modern periodic table shows atomic numbers of elements.
true
400
What is the chemical symbol for lead?
Pb
400
Matter changes from a liquid to a gas when ...
a-chemical properties change
b-molecules become more strongly linked
c-temperature decreases
d-molecules can move in all directions
d-molecules can move in all directions
500
What is an isotope?
One of a group of atoms of an element with the same number of protons but different numbers of neutrons.
500
An electron is a type of particle known as a ____________.
lepton
500
Elements that are found on the left of the periodic table are nonmetals.
false, metals
500
The smallest part of an element that has all the element's properties is ________________.
an atom
500
Which of the following elements is radioactive?
lead
hydrogen
gold
uranium