Which of the following options correctly describes atoms? Select all that apply.
An atom is the smallest unit of an element that can exist as a stable, independent entity
Atoms are extremely small
Compounds contain two or more different types of atoms
Atoms are divisible by ordinary chemical processes
Elements are made up of several types of atoms
Which of the following options correctly describe the periodic table? Select all that apply.
The horizontal rows in the periodic table are called groups
The elements in the periodic table are arranged based on similar chemical properties
The periodic table includes compounds as well as elements
The periodic table contained the chemical symbols that represent the elements
Elements found on the left side of the periodic table are called nonmetals
What group are Nobel gases apart of?
Group 1
Group 2
Group 17
Group 18
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.
Exponent
Scientific
Factor of 10
Condensed
Which of the following options correctly describes elements and compounds?
The substance N2 is an example of a compound
There are many more known compounds than elements
Elements and compounds are both pure substances
A compounds contains two or more different elements
A compounds is a mixture
Express 2.6 x 10^4 in decimal notation
260,000
260
26,000
26
The periodic table is organized such that elements with similar ______ properties fall into vertical columns called ________.
Physical; groups
Physical; periods
Chemical; groups
Chemical; periods
Which of the following statements correctly describes subatomic particles? Select all that apply.
Protons are positively charged
The mass of an electron is much smaller than the mass of a proton
A neutron is much heavier than a proton
The electrons are located outside the nucleus of an atom
The charge on a neutron is equal but opposite to the charge on 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.
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
The atomic number equals the number of neutrons present in the atom
Each element has its own unique atomic number
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^-11
8.35 x 10^10
8.35 x 10^-10
Which of the following are allotropes of oxygen?
O2
O3
CaO
CO2
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.
neutrons; protons
Electrons; protons
Protons; neutrons
Protons; electrons
Most elements occur in nature as _____________.
Single atoms
Diatomic molecules
Compounds
Minerals are _____________________.
Chemical compounds found in rocks and soil
Complex mixtures of metallic compounds
Diatomic molecules like N2
Elemental forms of metal found in the earth
Different forms of the same element (such as O2 and O3) are called ___________. These forms differ in the way atoms are bonded together.
Allotropes
Isotopes
Isotropes
Isomers
Which of the following are common types of minerals found in rocks and soil? Select all that apply.
Carbides
Nitrides
Oxides
Silicates
Aluminates
Which of the following options correctly describes the form(s) in which elements exist in nature? Select all that apply.
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.
Most elements exist as diatomic molecules such as O2
The composition of a mixture may be expressed as a percentage. Percent means parts per
Hundred
BIllion
Thousand
Million
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.
Rusting of iron
Boiling water
Cutting aluminum foil
Burning a candle
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 ____________.
Metalloid; nonconductor
Metal; semiconductor
Nonmetal; nonconductor
Metalloid; semiconductor
If a mixture of quartz and bauxite contains 78% quartz, this means that ________. (Select all that apply).
200 g of this mixture contains 22g of bauxite
There are 78g of quartz for every 100g of bauxite
There are 78g of quartz for every 22g of bauxite
150g of this mixture contain 117g of quartz
There are 78g of quartz in 100g of the mixture
Which of the following are physical changes? (Select all that apply.)
Tarnishing of silver
Melting ice
Breaking a bottle
Burning gasoline
Which metalloid is a key component of electronic devices?
Chromium
Iron
Sodium
Silver
Silicon
Silica is a naturally occurring oxide of silicon, SiO2, which is transparent. Pure crystalized SiO2 is known as ___________.
Sapphire
Diamond
Glass
Quartz
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
100,000
10,000
1,000,000
Silica glass is made by ________________.
Heating sand with acid to break the highly ordered structure so that it can harden and form glass when cooled
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
Which of the following options correctly describe silica? Select all that apply.
Quartz is a form of silica
Silica is naturally occurring substance
Pure silica is a highly colored substance
Silica is a form of pure, elemental silicon
Silica has a well-ordered structure composed of repeating linkages between Si and O
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 ________________.
Glass; entropic
Glass; amorphous
Crystal; entropic
Crystal; amorphous
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.
Potassium
Aluminum
Baron
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.
Cradle-to-grave
Production/disposal
Recycling
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?
Material extraction and processing
Laptop fabrication
Use by consumers
Recycling and/or disposal
What are the environmental challenges to extracting metals from recycled electronic devices? Select all that apply.
The solvents used to remove the plastics are not generally environmentally friendly
Contaminated groundwater could contribute to an increase of cancers in surrounding communities
The process is very costly in energy, more so than mining the metals from the ground
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 waste products created when the goods are made
Products that can be made from the goods
The raw materials from which the goods are made
The energy consumed to produce the goods
A "cradle-to-grave" approach to analysis of the life cycle of an item includes that ideas that ________________.
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
The life cycle of an item should be described in detail from its manufacture to its disposal
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 ____________.
Boiling in solvents
Treatment with strong acid
Crushing the circuit boards and then filtering out the metals
Physically picking them out with forceps
Which of the following are elements? Select all that apply.
CaCo3
NaCl
Cu
Na
Which of the following are examples of mixtures? Select all that apply.
Nitrogen gas
Argon
Carbon dioxide
Tap water
Soil
Chemistry is the study of _______________. Select all the options that correctly complete the sentence.
The properties of substances
The interaction of living systems
The changes of matter
Matter and its composition
Which of the following are pure substances? Select all that apply.
H2O
N2
Salt water
A molecule is an independent structure composed of two or more _____________ chemically bonded together.
Atoms
Elements
Which of the following elements commonly occur as diatomic molecules? Select all that apply.
Fluorine
Hydrogen
Nitrogen
Oxygen
Neon
