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Which of the following options correctly describes atoms? Select all that apply.
Compounds contain two or more different types of atoms
Elements are made up of several types of atoms
An atom is the smallest unit of an element that can exist as a stable, independent entity
Atoms are divisible by ordinary chemical processes
Atoms are extremely small
Which of the following options correctly describe the periodic table? Select all that apply.
Elements found on the left side of the periodic table are called nonmetals
The periodic table includes compounds as well as elements
The elements in the periodic table are arranged based on similar chemical properties
The periodic table contained the chemical symbols that represent the elements
The horizontal rows in the periodic table are called groups
What group are Nobel gases apart of?
Group 17
Group 1
Group 18
Group 2
What group are halogens apart of?
What group are alkali metas apart of on the periodic table?
What group are alkaline earth metals apart of on the periodic table?
The number 10,000 can be expressed as 1 x 10^4. This second form is called ______ notation.
Scientific
Exponent
Factor of 10
Condensed
Which of the following options correctly describes elements and compounds?
A compounds is a mixture
Elements and compounds are both pure substances
A compounds contains two or more different elements
There are many more known compounds than elements
The substance N2 is an example of a compound
Express 2.6 x 10^4 in decimal notation
26
260
260,000
26,000
The periodic table is organized such that elements with similar ______ properties fall into vertical columns called ________.
Chemical; periods
Chemical; groups
Physical; groups
Physical; periods
Which of the following statements correctly describes subatomic particles? Select all that apply.
The charge on a neutron is equal but opposite to the charge on a proton
A neutron is much heavier than a proton
The electrons are located outside the nucleus of an atom
Protons are positively charged
The mass of an electron is much smaller than the mass of a proton
Elements in Group 17 are called , whereas elements in Group 18 are called gases.
Which of the following statements correctly describe the atomic number of an element? Select all that apply.
Each element has its own unique atomic number
The atomic number equals the number of neutrons present in the atom
The atomic number of an element varies depending on the number of electrons present
The atomic number is equal to the number of protons in the nucleus
Scientific notation expresses a quantity with a single digit before the decimal point and followed by raised to the appropriate power.
Express the quantity 0.0000000000835 correctly in scientific notation.
8.35 x 10^-11
8.35 x 10^10
8.35 x 10^-10
8.35 x 10^11
Which of the following are allotropes of oxygen?
CO2
O3
O2
CaO
Each element has a unique number of ___________, which is called the atomic number. For a neutral atom, this number is also equal to the number of ___________ present.
Protons; electrons
Protons; neutrons
neutrons; protons
Electrons; protons
Most elements occur in nature as _____________.
Compounds
Single atoms
Diatomic molecules
Minerals are _____________________.
Diatomic molecules like N2
Elemental forms of metal found in the earth
Complex mixtures of metallic compounds
Chemical compounds found in rocks and soil
Different forms of the same element (such as O2 and O3) are called ___________. These forms differ in the way atoms are bonded together.
Allotropes
Isomers
Isotopes
Isotropes
Which of the following are common types of minerals found in rocks and soil? Select all that apply.
Carbides
Oxides
Nitrides
Aluminates
Silicates
Which of the following options correctly describes the form(s) in which elements exist in nature? Select all that apply.
Most elements exist as diatomic molecules such as O2
Nonmetals such as oxygen and nitrogen may occur either in elemental form in the form of compounds
Most metals can be mined from the earth in their pure, elemental states
Many metals exist as compounds of oxygen, or oxides.
The composition of a mixture may be expressed as a percentage. Percent means parts per
Million
Thousand
Hundred
BIllion
Solid compounds of metals found in rocks and soil are called ________.
Mineral
Ores
Which of the following are examples of chemical change? Select all that apply.
Boiling water
Cutting aluminum foil
Burning a candle
Rusting of iron
Many metals occur as minerals in rocks and soil. A mineral in which a metal is bonded to oxygen is called an . whereas a mineral containing oxygen and silicon together is called an .
Silicon is a key component of electronic devices. This element is an ___________, a type of element also called an ____________.
Metal; semiconductor
Metalloid; nonconductor
Metalloid; semiconductor
Nonmetal; nonconductor
If a mixture of quartz and bauxite contains 78% quartz, this means that ________. (Select all that apply).
There are 78g of quartz for every 22g of bauxite
There are 78g of quartz in 100g of the mixture
200 g of this mixture contains 22g of bauxite
150g of this mixture contain 117g of quartz
There are 78g of quartz for every 100g of bauxite
Which of the following are physical changes? (Select all that apply.)
Melting ice
Tarnishing of silver
Burning gasoline
Breaking a bottle
Which metalloid is a key component of electronic devices?
Iron
Chromium
Silicon
Sodium
Silver
Silica is a naturally occurring oxide of silicon, SiO2, which is transparent. Pure crystalized SiO2 is known as ___________.
Sapphire
Quartz
Diamond
Glass
Crystal is a solid that is ________________________________________________.
Disordered/random arrangement of constituent particles
Highly ordered arrangement of constituent particles
Amorphous solids are _________________________________.
1 ppm is _____ times smaller than 1%
1000
10,000
100,000
1,000,000
Silica glass is made by ________________.
Heating sand to a temperature high enough to melt it and then cooling the liquid until it hardens
Heating graphite (carbon) at high temperature under high pressure
Heating sand with acid to break the highly ordered structure so that it can harden and form glass when cooled
Which of the following options correctly describe silica? Select all that apply.
Silica has a well-ordered structure composed of repeating linkages between Si and O
Pure silica is a highly colored substance
Silica is naturally occurring substance
Silica is a form of pure, elemental silicon
Quartz is a form of silica
A solid that has a highly ordered structure at the atomic level is referred to an an ___________, whereas solids with a relatively disordered structure are described as ________________.
Crystal; entropic
Glass; amorphous
Crystal; amorphous
Glass; entropic
glass is strengthened glass that has been heated to high temperatures and cooled, which results in internal stresses.
Which of the following elements are commonly added to sand when making glass, to improve thermal properties? Select all that apply.
Baron
Aluminum
Potassium
An approach to analyzing the life cycle of an item, beginning with the raw materials from which it is made to its ultimate disposal, is called the ___________ approach.
Recycling
Production/disposal
Cradle-to-grave
The process of quickly cooling molten glass has the effect of the material.
An approach to consumer goods that aims at recycling, so that the end of the life cycle of one item loads naturally into the beginning of the life cycle of another, is the __________ approach.
The conversion of sand into high-purity silicon for computer chip fabrication would fall under which life cycle analysis for a laptop computer?
Laptop fabrication
Material extraction and processing
Use by consumers
Recycling and/or disposal
What are the environmental challenges to extracting metals from recycled electronic devices? Select all that apply.
The process is very costly in energy, more so than mining the metals from the ground
Contaminated groundwater could contribute to an increase of cancers in surrounding communities
The solvents used to remove the plastics are not generally environmentally friendly
Groundwater could be contaminated with heavy metals
Which if the following form the focus of the cradle to grave approach to consumer goods? Select all that apply.
The raw materials from which the goods are made
The energy consumed to produce the goods
Products that can be made from the goods
The waste products created when the goods are made
A "cradle-to-grave" approach to analysis of the life cycle of an item includes that ideas that ________________.
The life cycle of an item should be described in detail from its manufacture to its disposal
The end of the life cycle of one item leads naturally into the beginning of the life cycle of another
The end of the life cycle of an item can be defined precisely
Which of the following are essential parts of life cycle analysis? Select all that apply.
Marketing expenses
Research and development
Recycling and disposal
Fabrication
When an electronic device is recycled, the metals are recovered by ____________.
Physically picking them out with forceps
Crushing the circuit boards and then filtering out the metals
Treatment with strong acid
Boiling in solvents
Which of the following are elements? Select all that apply.
NaCl
Cu
CaCo3
Na
Which of the following are examples of mixtures? Select all that apply.
Nitrogen gas
Soil
Tap water
Argon
Carbon dioxide
Chemistry is the study of _______________. Select all the options that correctly complete the sentence.
The changes of matter
Matter and its composition
The properties of substances
The interaction of living systems
Which of the following are pure substances? Select all that apply.
Salt water
H2O
N2
A molecule is an independent structure composed of two or more _____________ chemically bonded together.
Elements
Atoms
Which of the following elements commonly occur as diatomic molecules? Select all that apply.
Hydrogen
Fluorine
Neon
Oxygen
Nitrogen