The subatomic particles that make up atoms are _______. 1.neutrons, electrons, & positives 2.electrons, neutrons, & protons 3.protons, electrons, & negatives 4.positives & negatives
Having the same number of protons & electrons, all isotopes of an element have the same ___________________. 1.chemical properties 2.physical properties 3.mass 4.compounds
A chemical bond that is formed by the transfer of electrons is a(an) ___________________ 1.ionic bond 2.covalent bond 3.polar bond 4.nonpolar bond
If an atom has 8 neutrons and 8 protons, it must have ____ electrons
What forces are the design of a gecko’s feet that enables it to climb up vertical surfaces 1.Gravity 2.Van der Waals 3.Van Trappe 4.None of these
Your stomach produces this to help digest food. 1.Saliva 2.Water 3.Insulin 4.Acid
The pH scale is a measurement system that measures the concentration of _______ in a solution 1.H - 2.H + 3.O - 4.O +
These are weak acids or bases that can react with strong acids or bases to prevent sudden changes in pH. 1.Products 2.Reactants 3.Buffers 4.Chlorides
A substance with a pH of 8 is called 1.an acid. 2.a base. 3.both an acid and a base. 4.neither an acid nor a base.
The smallest part of a compound is 1.an element 2.a molecule 3.an atom 4.a miracle
The smallest part of an element is 1.an atom 2.a molecule 3.a compound 4.a speck of dust
What is a mixture? 1.when substances are combined both chemically and physically 2.when substances are combined just chemically and not physically 3.when substances are combined not chemically just physically 4.when substances can’t be combined neither chemically nor physically
Ice floats on water because 1.of cohesion. 2.ice has a higher density than water. 3.water shrinks when it freezes. 4.water expands when it freezes
When salt is dissolved in water, water is the 1.solution. 2.solute. 3.solvent. 4. mixture.
A substance with a pH of 6 is called 1.an acid. 2.a base. 3.a buffer. 4.None of these
What type of ion forms when an atom loses electrons? 1.Positive 2.Negative 3.Neutral 4.Depends on how many electrons are lost
Which of the following is a use of radioactive isotopes? 1.can determine the ages of rocks and fossils. 2.can be used to treat cancer & kill bacteria that cause food to spoil. 3.used as “tracers” to follow the movements of substances within organisms. 4.all of the above
Chemical reactions that release energy 1.will explode. 2.will not occur. 3.will always explode. 4. often occur spontaneously.
The space surrounding the nucleus of an atom contains 1.neutrons. 2.protons. 3.electrons. 4.all of these.
What is the term used to describe the energy needed to get a reaction started? 1.adhesion energy 2.cohesion energy 3.activation energy 4. chemical energy
What is the process that changes one set of chemicals into another set of chemicals? 1.Cohesion 2.Adhesion 3.Dissolving 4.Chemical reaction
Suspensions are mixtures 1.of water and nondissolved material. 2.in which the components are evenly distributed throughout the solution. 3.both a and b 4.neither a nor b
Solutions that contain concentrations of H+ ions lower than pure water 1.are acids. 2.are bases 3.are buffers 4.are enzymes.
A covalent bond is formed as the result of 1.transferring electrons. 2.sharing electrons. 3.transferring protons. 4.sharing protons.
Isotopes are atoms of the same element with the same number of protons and 1.neutrons. 2.electrons. 3.masses. 4.molecules.
Which of the following terms describes a substance formed by the combination of two or more elements in definite proportions ? 1.Element 2.Chemical 3.Molecule 4.Compound
The nucleus of an atom contains 1.protons & neutrons. 2.electrons & protons. 3.electrons & neutrons. 4.any of these.
If an atom contains 11 protons, 12 neutrons, its atomic number is?