Unit 3 Exam Flashcards
Which contribution is a modification to Thomson’s plum pudding model?
A positively charged nucleus sits at the center of an atom.
An atom with 4 protons, 5 neutrons, and 4 electrons has an atomic mass of
9 amu
Which of the following statements does not describe the structure of an atom?
Inside the nucleus of an atom are protons and neutrons.
Protons are positively charged sub-atomic particles.
Electrons are negatively charged sub-atomic particles.
Most of the mass of an atom comes from the electron cloud.
Most of the mass of an atom comes from the electron cloud.
FALSE
There are more electrons than protons in a negatively charged atom. T/F?
True
A neutral atom of aluminum has 13 protons and how many electrons
13
Which of the following elements has the highest atomic mass? Helium: 2 protons and 2 neutrons Nitrogen: 7 protons and 7 neutrons Oxygen: 8 protons and 8 neutrons Hydrogen: 1 proton and no neutrons
Oxygen: 8 protons and 8 neutrons
Ernest Rutherford
Positively charged nucleus
J.J. Thomson
Plum pudding model
John Dalton
Atoms indivisible
James Chadwick
Discovery of neutrons
Which of the following elements has the largest atomic radius? Silicon Aluminum Sulfur Phosphorous
Aluminum
Which of the following elements is the most reactive? Beryllium Calcium Magnesium Barium
Barium
Neon
Nonreactive gas
Boron
Has properties of both metals and nonmetals
Barium
Great conductor of heat and electricity
Potassium
Malleable and highly reactive
A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have?
5
The element chlorine is represented by the symbol
Cl
Use your periodic table of elements. Take any element from the first column, except for hydrogen and lithium, and answer the following questions:
What is the element’s name and symbol?
Is it a metal, nonmetal, or metalloid?
Which family does it belong to?
How many protons, neutrons, and electrons does its neutral atom have?
Francium
- Fr, Francium
- Francium is a non-metal
- Francium belongs to the alkali metal family.
- Francium 87 Protons, 136 Neutrons, 87 Electrons
Which item is made from a basic ingredient?
Toothpaste
Which description is not a property of a base?
Turns litmus paper red
Bitter taste
Caustic
pH higher than 7
Turns litmus paper red
Ion
An atom or molecule that has a positive or negative charge
Acid
A compound that increases hydrogen ions (H+) when it is dissolved in a solution
Alkaline
A compound that increases the hydroxide ions (OH−) when it is dissolved in a solution
pH
A value from 0 to 14 that is used to specify how acidic or basic a compound is when it is dissolved in water
Which description is not a property of an acid?
Sour taste
Corrosive
Slimy feel
Dissolves metals
Slimy feel
Which number represents an acidic pH, 4 or 9
4
Which description of salt is a physical property?
No combustion
Makes ionic bonds
Product of mixing acids and bases
Solid does not conduct electricity
Solid does not conduct electricity
Which substances will make a salt when combined?
Vinegar and antacids
Soda and wine
Soap and ammonia
Fertilizer and detergent
Vinegar and antacids
Which of the following techniques can be used to separate a homogeneous mixture into its component parts?
Apply pressure
Heterogeneous mixtures can be physically separated into their individual components.
T/F?
True
Heterogeneous
Mixture that has its different components mixed unevenly within the substance
Colloid
A mixture in which microscopically insoluble particles are suspended throughout another substance
Emulsion
A mixture in which two or more liquids are mixed that normally are not mixable
Homogeneous
Mixture that has its different components mixed evenly within the substance
What makes a pure substance different from a heterogeneous mixture?
The components of a pure substance are single elements or compounds instead of a mixture of compounds.
The process of filtration was used to separate a sample into its components. What conclusion about the sample can be formed based on the technique used?
It was a heterogeneous mixture.
Which substance is a heterogeneous mixture
Cereal
Silver
Nickel
Shampoo
Cereal
