Science 6 Midterm Exam Review

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melting point
The specific temperature at which a solid changes to a liquid
fluid
another name for a liquid
melting point
specific temperature at which a solid changes to a liquid
tracers
can be used to find weak spots in metal pipes and to detect medical problems
vaporization
the change from a liquid to a gas
viscosity
a liquid's resistance to flowing
semiconductors
substances that can conduct electricity under some conditions but not others
synthetic
elements with atomic numbers higher than 92 are sometimes called by this name because they are not found naturally on Earth
lithium
this alkali metal is used to make batteries and some medicine
halogen
a word meaning salt forming
reactivity
the ease and speed with which an element combines, or reacts with other elements and compounds
alloy
a mixture of a metal and at least one other element usually another metal
technology
a way of changing the natural world to meet human needs or solve problems
trade-off
an exchange in which one benefit is given up in order to obtain another
atom
the basic particle from which all elements are made
compound
a pure substance made of 2 or more elements chemically combined in a set ratio
freezing
the change of state from a liquid to a solid
condensation
takes place when you breathe warm air onto a mirror and water droplets are formed
tarnishing
slow combination of a metal with sulfur or another substance, producing a dark coating on the metal
hypothesis
possible explanation for a set of observations or an answer to a scientific question
kinetic
energy of matter in motion
potential
energy an object has because of its position
chemical
internal energy stored in the chemical bonds between atom
electromagnetic
a form of energy that travels through space waves
thermal
the total energy of all particles in an object
potential
the form of energy a book has when lying on a desk
kinetic
the form of energy a book has when falling off of a desk
oxidation
slow combination of a substance with oxygen
fuel
combustion is rapid combination of a ________ with oxygen. It produces heat, light, and new substances
combustion
burning is an example
dark
silverware turning ____ is an example of tarnishing
physical
property of a pure substance that can be observed without changing it into a new substance (chemical or physical)
chemical
this property is a characteristic of a pure substance that describes its ability to change into different substances (chemical or physical)
chemical formula
combination of symbols that shows the ratio of elements in a compound
bond
chemical _______ is the force of the attraction that holds two atoms together as a result of the arrangement of electrons between them (chemical or physical)
heterogeneous
In this type of mixture you can see the different parts
heterogeneous
sand mixed with water is an example of this type of mixture
gas
during sublimation particles of a solid do not pass through the liquid state as they form a ____
high
the viscosity of honey is (high or low or unknown)
dry ice
a common name for solid carbon dioxide
solid
has a definite shape and volume
liquid
has definite volume but no shape of its own
uncuttable
atomos comes from the greek word meaning___
negative
charge of electrons (positive, negative, neutral)
nucleus
the center of an atom
positive
charge of protons (positive, negative, neutral)
electrons
found in the cloudlike area around the nucleus
neutrons
neutral particles found in the nucleus of the atom are called____
8
number of protons in every oxygen atom
6
number of protons in every carbon
mass number
the sum of protons and neutrons in the nucleus of the atom
Mendeleev
Russian scientist who discovered a set of patterns that applied to all elements
sun
object made mostly of hydrogen
mercury
a metal element that is a liquid at room temperature
ion
an atom or group of atoms that has an electric charge
technological systems
components of this system include these components (goal, inputs, processes, outputs)
semiconductors
used to make computer chips, transistors, lasers
Fe2O3
chemical formula for rust
oxygen
the most abundant element in the earth's crust
nitrogen
the most abundant element in the earth's atmosphere
oxygen
most hydrogen is combined with what element?
radioactive decay
alpha and beta and gamma are products of ____
rearranged
atoms can be _______ in a chemical change
same
Every atom of the SAME element has the ______ number of protons
atoms
all elements are composed of ____ that cannot be divided
isotope
an atom with the same number of protons and a different number of neutrons for other atoms of the same element
properties
_____ of an element can be predicted from its location in the periodic table
families
the vertical columns or groups in a periodic table are sometimes known as ________.
transition metals
include most of the familiar metals, such as iron, copper, nickel, silver and gold. Most of these metals are hard and shiny. All of these are good conductors of electricity.
alkali
These metals are so reactive that they are never found as uncombined elements in nature
silicon dioxide
the main component of glass
lithium
an alkali metal used to make batteries.
gamma rays
rays which can pass through paper and aluminum foil
alpha rays
these rays can be blocked by paper
destroyed
atoms cannot be created nor _______ in a chemical reaction
periodic chart
hydrogen is not grouped into a family on the ____ because it is not like any other element
condensation
an example is when you breathe warm air onto a mirror and water droplets form
hydrogen
element which is rarely found in Earth as a pure element (It is usually combined with oxygen to form water.)
identify
melting point is a characteristic property of a substance, chemists often use when trying to__________ unknown substance.
gas
instead of melting dry ice changes directly into _____
mass
does not change with the pull of gravity.
air pressure
because of this, the boiling point of water is not the same at the top and the bottom of a mountain
weight
changes with the pull of gravity.
radiation therapy
radioactive particles are used to destroy unhealthy cells
melting
the change in state from a solid to a liquid
reaction
for every action there is an equal and opposite _______
conductivity
the ability of an object to transfer heat or electricity to another object
malleable
can be hammered or rolled into flat sheets and other shapes
shininess
ability to reflect light
density
mass divided by volume equals (This is the formula for___).
neutral
the charge of neutrons (positive or negative or neutral)
need
In the Technology Design process scientists must identify the problem or _____
research
In the Technology Design process scientists must study or ___ the problem
hypothesis
In the Technology Design process scientists must design an answer (guess) or _____
prototype
In the Technology Design process scientists must build a model and/or ____
redesign
In the Technology Design process scientists must troubleshoot then ___
share
In the Technology Design process scientists must communicate or ___ the solution
electrolysis
use of electricity to break a compound into elements or simpler compounds