CEM 141 Ch1 & Stoichiometry Exam
Questions And Detailed Answers.
A Scientific Model - Answer Can be a drawing or a graph or a diagram or an equation, physical
or mental.
Claim - Answer The target of your explanation.
Evidence - Answer The data or scientific principle you are using to support your claim.
Reasoning - Answer The connection between your claim and evidence.
Law - Answer Describes the phenomenon. (Tells you what)
Theory - Answer Explains the phenomenon. (Tells you why)
Dalton's Atomic Theory - Answer 1. Elements are composed of small indivisible, indestructible
particles called atoms.
2. All atoms of an element are identical and have the same mass and properties.
3. Atoms of a given element are different from atoms of other elements.
4. Compounds are formed by combinations of atoms of two or more elements.
5. Chemical reactions are due to the arrangements of atoms; atoms (matter) are neither created
nor destroyed during a reaction.
Cathode Ray tube - Answer Glass tube consisting of two electrodes under very low pressure.
When a high voltage is applied, cathode emits "particles" that move toward anode.
Alpha particle - Answer An alpha particle has two protons and two neutrons. It is the nucleus
of a helium atom.
Neutrons - Answer - Neutral in charge-- not manipulated with electric and magnetic fields.
- Reside in nucleus.
Questions And Detailed Answers.
A Scientific Model - Answer Can be a drawing or a graph or a diagram or an equation, physical
or mental.
Claim - Answer The target of your explanation.
Evidence - Answer The data or scientific principle you are using to support your claim.
Reasoning - Answer The connection between your claim and evidence.
Law - Answer Describes the phenomenon. (Tells you what)
Theory - Answer Explains the phenomenon. (Tells you why)
Dalton's Atomic Theory - Answer 1. Elements are composed of small indivisible, indestructible
particles called atoms.
2. All atoms of an element are identical and have the same mass and properties.
3. Atoms of a given element are different from atoms of other elements.
4. Compounds are formed by combinations of atoms of two or more elements.
5. Chemical reactions are due to the arrangements of atoms; atoms (matter) are neither created
nor destroyed during a reaction.
Cathode Ray tube - Answer Glass tube consisting of two electrodes under very low pressure.
When a high voltage is applied, cathode emits "particles" that move toward anode.
Alpha particle - Answer An alpha particle has two protons and two neutrons. It is the nucleus
of a helium atom.
Neutrons - Answer - Neutral in charge-- not manipulated with electric and magnetic fields.
- Reside in nucleus.
