Chemistry Chapter 3 Test Review

What is the complete symbol for a cobalt atom with a mass number of 60? A) 60. B) 33 37 Co 37 Co C) 37 D) 33 37 Co 60 Co

60 A) 37 Co

The ______ has a positive charge and is located in the nucleus. A) proton B) electron C) atom D) nuetron

A) proton

How should you find the molar mass of any given element? A) the molar mass is the same as the mass number B) convert the molar mass from the mass given C) you must be given the molar mass, you can't calculate it D) use Avogadros' number

A) the molar mass is the same as the mass number

Magnesium- 25 has _____ protons and _______ nuetrons. A) 12,25 B) 12,13 C) 25,12 D) 25,13

B) 12, 13 ( because only answer with 2 seperate parts that go into 25 )

What is the molar mass of oxygen? A) 8 g/mol B) 16 g/mol C) 6 g/mol D) 16 grams

B) 16 g/mol

What do chemists use moles for?

A chemistry measurement unit

How many electrons does the following ion have? 34 12 Mg 2 + A) 10 B) 12 C) 14 D) 22

A) 10 (because you multiply 12 by 2 to get 24, then you minus 34-24)

157 moles of hydrogen (H) have a mass of: A) 157 g B) 6.022 * 10 ^ 23 g C) 314 g D) 1.008 g

A) 157 g

How many's grams is one mole of sodium ( Na)? A) 23 B) 34 C) 11 D) 1

A) 23

Given that the number of electrons is 42 find the number of protons given the mass number is 96. A) 42 B) 95 C) 54 D) 138

A) 42 because the number is the same as number of electrons.

How many protons are in the following atom? Example: 207 Pb 82 A) 82 B) 125 C) 207 D) 189

A) 82

In a hyphenated symbol ( fluorine- 19 ) the 19 is the A) mass number B) group number C) atomic num er D) average atomic mass

A) The mass number.

What does the law of conservation of mass state? A) matter cannot be created of destroyed B) matter can be created but not destroyed C) matter cannot be created but it can be destroyed D) matter can be created and destroyed

A) matter cannot be created or destroyed

You have 3 moles of H20. How much mass is this? A) 18 g/mol B) 54 g/mol C) 36 grams D) 32 grams

B) 54 g/mol

A neutral carbon atom has... A) 3 electrons and 3 nuetron B) 6 protons and 6 electrons C) 3 protons and 3 electrons D) none of these

B) 6 protons and 6 electrons

How many neutrons are in the nucleus of the following atom... Example: Ag 108 47 A) 47 B) 61 C) 108 D) 155

B) 61

How many nuetons are in the isotope Carbon-14? A) 6 B) 8 C) 12 D) 14

B) 8 - Carbon's top number is 8 so 14-6 is 8

The number of protons + neutrons in an atomic nucleus is referred to as what? A) Atomic Number B) Atomix Mass C) Isotope number D) Electron Balance

B) Atomic Mass

An ion with a positive charge... A) contains more electrons than the neutral atom B) contains less electrons than the neutral atom C) contains the same amount of electrons as the neutral atom D) none of these

B) Contains less electrons than the neutral atom

The term "atom" comes from the Greek philosopher named? A) Aristotle B) Democritus C) Galileo D) Socrates

B) Democritus

Experiments with cathode rays Resulted in the discovery of? A) Atoms B) Electrons C) Protons D) Nuetrons

B) Electrons

Atoms of the same element with differing number of neutrons are called A) elements B) isotopes C) Ions D) none of these

B) Isotopes

What weighs more, 2 moles of phosphorous (P), or 4 moles of Sodium ( NA ) ? A) P B) Na

B) Na

Which subatomic particle is used to identify the atom, as it never changes? A) Electron B) Proton C) Nuetron D) none of these

B) Proton

What does the atomic number identify? A) The number of nuetrons of a given atom. B) The number of protons of a given atom. C) The number of protons + nuetrons of a given atom. D) The number of electrons of a given atom.

B) The number of protons of a given atom.

What is the 1st step in calculating the average atomic mass of isotopes? A) multiply by the percentages B) add the masses together C) multiply the masses by the percentages D) multiply by 100

B) add the masses together

The ______ has a negative charge and is located outside the nucleus. A) proton B) electron C) nuetron D) atom

B) electron

Which particle has the smallest mass? A) proton B) electron C) nuetron D) ion

B) electron

1 mole is equal to: A) the mass of an element B) the number of atoms contained in 12 grams of C12 C) the number of protons D) the number of protons and the number of nuetrons

B) the number of atoms contained in 12 grams of C12

How many electrons does the following ion have? 14 7 N 3 - A) 3 B) 7 C) 10 D) 14

C) 10 ( because you take the 7 and add the 3 )

How many protons does 28 Al 13 Have? A) 28 B) 41 C) 13 D) 15

C) 13

The molar mass of calcium fluoride, CaF2, is ( hint- add molar mass of individual atoms). A) 59.08 g/mol B) 118.16 g/mol C) 78.08 g/mol D) 40.08 g/mol

C) 78.08 g/mol ( using periodic table)

How many grams are two moles do helium ( He) ? A) 4 B) 1 C) 8 D) 12

C) 8

Given the mass number is 14 and the the number of protons is 6, find the number of neutrons. A) 12 B) 6 C) 8 D) 14

C) 8 ( by doing 14 - 6 )

Which of Dalton's postulates incorporates the Law of Conservation of Mass? A) All matter is composed of atoms B) Atoms from the same elements are identical C) Atoms can be combined, seperated or rearranged D) Atoms are indivisible

C) Atoms can be combined, seperated or rearranged

This law states " a compound always contains the same elements in exactly the same proportion" A) law of conservation of mass B) law of conservation of energy C) law of definite proportions D) law of multiple proportions

C) law of multiple proportions

The ______ has no charge and is located in the nucleus. A) proton B) electron C) nuetron D) atom

C) nuetron

Given the mass number is 63 and number of protons is 29, find the number of neutrons. A) 81 B) 29 C) 64 D) 34

D) 34 ( do 63 - 29 )

Strontium 90 has a mass number of? A) 38 B) 27 C) 52 D) 90

D) 90 ( number on top of Stronium on Periodic Table )

All isotopes of an element have the same atomic number, true or false?

True