Chapter 1
True or False
The smallest particle of an element is called a(n) atom.
True
In which state of matter do the particles spread apart and fill all the space available to them?
gas
protons
True or False
A low melting point is one property of molecular compounds.
True
What is the principle of conservation of mass?
Mass is neither created nor destroyed during all reactions.
True or False
A substance that undergoes a chemical change is still the same substance after the change.
False
In which state of matter are particles packed tightly together in fixed positions?
solid
Does this describe columns or rows on a Periodic Table?
These elements have similar characteristics.
Columns
True or False
A nonpolar bond is formed when two atoms share electrons unequally.
False
Which system is described by having matter enter from or escape to the surroundings?
Open System
All elements are made of basic particles called
atoms
thermal
Double you points if you can tell me the most common element on Earth.
Hydrogen
Oxygen
Two pairs of electrons being shared between two atoms describes a
double bond
Every chemical reaction involves a change in
(Answer is not substance)
energy
Anything that has mass and takes up space is called
matter
What is vaporization?
a liquid becoming a gas
In the periodic table, the most reactive metals are found where?
In Group 1
When an atom loses an electron, it becomes a
positive ion
The only sure evidence for a chemical reaction is
Soil, a salad, and sugar water are all examples of
mixtures
What is the opposite of vaporization?
Groups 3-12 are called the _________ metals.
transition
Electrons involved in bonding between atoms are
valence electrons
Which two reactions could be considered opposites?
a synthesis reaction and a decomposition reaction
What holds atoms together in a molecule?
chemical bonds
What happens during the process of sublimation
solid turns directly into a gas
metalloids
Name the group that has the most reactive elements.
alkali metals
What is the name of the number placed in front of a chemical formula in an equation that helps balance the equation?
coefficient
What is the SI unit for mass?
kilogram
When an inflated balloon is exposed to cold air, what happens to its volume?
It decreases
What name is given to the part of the atom that contains the electrons?
electron cloud
In the chemical formula for an ionic compound, which item is written first?
the name of the positive ion
Chemicals that act as biological catalysts by speeding up reactions in living things are called
enzymes
The ability to do work or cause change describes
energy
The surface of water can act like a sort of skin due to a property of liquids called
surface tension
The atomic mass consists of
protons plus neutrons
Which compounds form hard, brittle crystals.
Ionic Compounds
Substances listed on the left side of a chemical equation are the
reactants
How would you calculate the density of an object?
Divide its mass by its volume
D= M/V
The resistance of a liquid to flowing is its
viscosity
Group 17 is so reactive that many of its elements are already in _________.
compounds
Electron dot diagrams show the _______ of an atom.
valence electrons
A chemical reaction that absorbs energy in the form of heat is described as
endothermic
The volume of an irregular object can be measured by
submerging the object in water in a graduated cylinder
When the temperature of a gas decreases, its
pressure decreases
The atomic number of an element is based on
the number of protons in the nucleus
What is a mixture made of two or more elements, with at least one of them being a metal?
alloy
The minimum amount of energy needed to start a reaction is the
activation energy