chemistry
A chemical change occurs when
a leaf changes color in the fall
A physical change occurs when
a leaf changes color in the fall
Which of the following is not a chemical change
melting
Which of these statements about density is true
Density is a physical property
IF a mixture is not uniform throughout, it is called
Heterogenous
It is easy to determine whether a substance is a metal if the substance is
a good electrical and heat conductor
the standard base unit for mass is the
kilogram
.05 cm is the same as
.5mm
A volume of 1 milliliter is equivalent to
1 cubic centimeter
100 milliliters is equivalent to
1 deciliter
how many minutes are in 1 week
10,080
the liter is define as
1000cm³
1.06 L of water is equivalent to
1060 mL
.25g is equivalent to
250 mg
0.000305 has how many significant figures
3
0.0320 has how many significant figures
3
the number of grams equal to .5 kg is
500
What is a heterogeneous mixture
A heterogeneous mixture is made of different substances that remain physically separate.
The relationship between the mass m of a material, its volume V, and its density D,
D=m/V
Density SI unit
Kg/m³, g/cm³, Kg/L, NOT g/m²
Which of these statements about mass is true
The mass of an object is determined by comparing it to an object of known mass
how should the numbers be rounded when finding the sum of numbers
The number being rounded so the hundreds or the biggest number place is rounded
Under ordinary conditions of temperature and pressure, the particles in a gas are
Very far from one another
A mixture is
a blend of any two or more kinds of matter, as long as each maintains its own unique properties
What is a pure substance
a chemical substance is a material with a specific chemical composition.
A homogeneous mixture is also called
a solution
A compound is
a substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances
A measurement that closely agrees with an accepted value is best described as
accurate
A solid substance is
always the same shape regardless of its container
A chemical can be defined as
any substance that has a definite compositon
Plasma is the fourth state of matter, in the plasma state
atoms lose electrons
A nonmetal is usually
brittle
Which of the following is not a physical change?
burning
The quantity of matter per unit volume is
density
Which of the following is an intensive property of matter
density
The density of an object is calculated by
dividing its mass by its volume
The vertical columns on the periodic table are called groups
groups
the liquid state of matter can be describe as
having a definite volume but not a definite shape
If a mixture is uniform in composition, it is said to be
homogeneous
What happens to the energy in a substance when it changes state?
it changes form, but is neither destroyed nor increased
Matter includes all of the following except
light
A state of matter in which a material has no definite shape but has a definite volume is the ___ state
liquid
What is the symbol that represents a unit of volume
mL
A measure of quantity of matter is
mass
The measure of the amount of material
mass
A true statement about is that
mass is determined by comparing the mass of an object with a set of standard masses that are part of a balance
The SI base unit for length is the
meter
A student recorded the following while completing an experiment Color of substance: yellow, shiny powder Effect of magnet: yellow, shiny powder was attracted The student should classify the substance as a
mixture
All known chemical elements are organized into groups based on similar chemical prperties in the
periodic chart
The horizontal groups on the periodic table are called
periods
If repeated measurements agree closely but differ widely from the accepted value these measurements are
precise but not accurate
Nitrogen monoxide and oxygen, both colorless gases, form a red-brown gas when mixed. Nitrogen monoxide and oxygen are called the
reactants
A numerical result is said to have good precision if
repeated measurements agree closely
The SI base unit for time is
second
Metalloids are often
semiconductors
The two most important properties of all matter are
taking up space and having volume
An atom is
the smallest unit of matter that maintains its chemical identity
When density is measured
the temperature should be specified
Noble gases are in group 18, and are best known because they are
unreactive
Which of the following is an extensive property of matter
volume
the unit m³ measures
volume
The pair of quantities determines the density of a material
volume and mass
A change in the force of gravity on an object will affect its
weight
The measure of Earth's gravitational pull on matter
weight
