Chemistry

A burning splint will burn more vigorously in pure oxygen than in air because____. A) oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air B) oxygen is a catalyst for combustion C) oxygen is a product of combustion D) nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature E) nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion - Answer A) oxygen is a ...

Atomic model - Answer Representation of an atom showing its nucleus and orbiting electrons. Proton - Answer Positively charge subatomic particle found in the nucleus. Neutron - Answer neutrally subatomic particle found in the nucleus. electron - Answer negatively charged subatomic paticle found in orbit around the nucleus subatomic - Answer within the atom pure substance - Answer 1 consistent particle (1 formula throughout). Mixture - Answer Homeogenous mixtures - Answer same consistency...

Found in the nucleus of the atom - Answer protons and neutrons Found in the rings outside of the nucleus - Answer electrons How many electrons fit in the first ring? - Answer 2 Only 2 electrons fit in the 1st ring. How many fit in all the other rings? - Answer 8 What do you call the electrons in the outermost ring? - Answer valence electrons These are the rows (left - right) on the periodic table - Answer periods These are the columns (up and down) on the periodic table - Answer groUPs Va...

physical change - Answer any change that changes the form or appearance of a substance but does not change it into another substance chemical change - Answer when the atoms rearrange to form new substances Reactants - Answer substances that undergo the chemical changes Products - Answer the new substance that forms Precipitate - Answer a solid that forms from liquids during a chemical reaction Exothermic reaction - Answer the energy released as the products form is greater than the energy...

Change in energy, Production of a gas, Formations of a precipitate, Color change - Answer Four evidences of Chemical Reactions Precipitate - Answer A solid that settles out of a solution as the result of physical or chemical changes Color change - Answer A physical change that shows a reaction has occurred Chemical equation - Answer A model of a chemical reaction that shows the chemicals used (reactants) and the chemicals produced (products); Reactants - Answer Left hand side of the equat...

Group 1 - Answer Alkali metals. Group 2 - Answer Alkaline earth metals Groups 3-12 - Answer transition metals metalloids - Answer Found along the 'staircase'. Have properties of both metals and nonmetals nonmetals - Answer brittle , dull, poor conductors of heat and electricity Proton - Answer Positively charged particle in the nucleus of an atom Neutron - Answer A subatomic particle that is neutral and that is found in the nucleus of an atom Electron - Answer A tiny, negatively charg...

Isotopes - Answer Atoms of the same element vary in the numbers of neutrons they have in the nucleus. Have different masses because of the different numbers of neutrons. Crystals - Answer Formed when atoms ionize by transferring electrons from one atom to another. Ex: sodium chloride, calcium chloride, calcium oxide. Moleucles - Answer A cluster of atoms chemically bonded together. Ex: water, ammonia, methane, carbon dioxide, propane, and sulfur dioxide. Acid Rain - Answer Sulfur dioxide...

Chemical Reaction - Answer Process in which one or more substances, are changed into new substances Reactants - Answer in a chemical reaction , the substance that reacts products - Answer in a chemical reaction the new substance or substances form chemical equations - Answer short hand method used to describe chemical reactions using chemical formulas and other symbols. Coefficients - Answer number in a chemical equation that represents the number of units of each substance taking part in...

phase change - Answer a switch between a phase of matter caused by a change in temperature or pressure average kinetic energy - Answer measure of how quickly particles are moving, measured as temperature temperature - Answer measure of average kinetic energy pressure - Answer the force of pushing or squeezing measure in atmospheres (atm) or kiloPascals (kPa) endothermic - Answer reaction that absorbs heat, heat enters the reaction and will be found on the reactant side of a chemical equa...

Period - Answer Elements in the same ____ have same size atoms. Group - Answer Elements in the same ____ have the same number of valence electrons. Top - Answer The smallest elements are towards the ___ of the periodic table. Bottom - Answer Bigger elements are toward the ___ of the periodic table. Transition Metals - Answer The name of the middle section of the periodic table. Noble Gases - Answer Group 18 of the periodic table. All electrons in that group have the maximum number of elect...