Deck 1: Introduction to Chemistry

Question 1

"Metals are good conductors of electricity" is a _____.

A) hypothesis
B) theory
C) law
D) qualitative observation
E) quantitative observation

Answer 1

law

Question 2

An alloy is a homogeneous mixture of two or more metals.

Answer 2

True

Question 3

A hypothesis is a tentative explanation for scientific observations that puts the system being studied into a form that can be tested.

Answer 3

True

Question 4

Which of the following is an intensive property of a material?

A) Mass
B) Volume
C) Density
D) Surface area
E) Weight

Question 5

Filtration is the best method for separating homogeneous mixtures.

Question 6

When dry salt is mixed with dry sugar it forms a(n) _____.

A) alloy
B) solid solution
C) heterogeneous mixture
D) homogeneous solution
E) colloid

Question 7

Atmospheric air is an example of a heterogeneous mixture.

Question 8

A _____ contains two or more elements and has chemical and physical properties that are usually different from those of the elements of which it is composed.

Question 9

Write a note on the physical and chemical properties of matter.

Question 10

A law attempts to explain why nature behaves as it does.

Question 11

Which of the following is an element?

A) Steel
B) Sugar
C) Lead
D) Air
E) Salt

Question 12

_____ are systematic observations or measurements, preferably made under controlled conditions.

A) Hypothesis
B) Theories
C) Laws
D) Experiments
E) quantitative observation

Question 13

Which of the following is an example of matter undergoing only a physical change?

A) Carbon (solid) being burnt in air to form carbon dioxide (a gas)
B) Hydrogen (gas) forming water with oxygen (gas)
C) Water (liquid) forming steam (gas) after being heated
D) Chlorine (gas) forming Hydrogen Chloride (liquid) when mixed with water
E) Sodium (solid) forming sodium hydroxide (aqueous) when mixed with water.

Question 14

Qualitative observations are measurements, which by definition consist of both a number and a unit.

Question 15

_____ observations describe properties or occurrences in ways that do not rely on numbers.

Question 16

Physical change is a process by which matter changes from one physical state to another.

Question 17

_____, by definition are measurements which consist of both a number and a unit.

A) Null hypotheses
B) Results
C) Qualitative observations
D) Alternate hypotheses
E) Quantitative observations

Question 18

_____ have neither fixed shapes nor fixed volumes.

Question 19

Which of the following mixtures would be best separated by filtration?

A) A solution of salt in water
B) An alloy of zinc and iron
C) A mixture of carbon dioxide and oxygen
D) A mixture of water and alcohol
E) A mixture of sand and gravel

Question 20

Explain how scientists use the scientific method to answer questions.

Question 21

According to Avogadro's hypothesis, one volume of hydrogen reacts with one volume of bromine to give two volumes of hydrogen bromide.

Question 22

The flammability and susceptibility to corrosion of a substance are examples of its _____ properties.

Question 23

_____ states that in any chemical reaction, the mass of the substances that react equals the mass of the products that are formed.

A) The law of conservation of mass
B) The law of definite proportions
C) The atomic theory of matter
D) The law of multiple proportions
E) The law of conservation of matter

Question 24

α rays are made of particles having the higher mass-to-charge ratio and subsequently have the least penetrative capability.

Question 25

Cathode rays consist of a stream of helium nuclei.

Question 26

The number of atoms in a volume of CO₂ is _____ to the number of atoms in a volume of H₂S.

Question 27

According to Avogadro's hypothesis the number of atoms in one volume of hydrogen (H₂) gas is _____ the number of atoms in one volume of ammonia (NH₃) gas.

A) half
B) equal to
C) double
D) three times
E) one fourth

Question 28

List out the four fundamental hypothesis of Dalton's atomic theory.

Question 29

The number of atoms in a volume of hydrogen chloride will equal the number of atoms in a volume of chlorine.

Question 30

The law of multiple proportions states that equal volumes of different gases contain equal numbers of gas particles.

Question 31

According to Avogadro's hypothesis, a volume of hydrogen gas would contain the same number of particles as a volume of liquid hydrogen.

Question 32

_____ states that when two elements form a series of compounds, the ratios of the masses of the second element that are present per gram of the first element can almost always be expressed as the ratios of integers.

A) The law of conservation of mass
B) The law of definite proportions
C) The atomic theory of matter
D) The law of multiple proportions
E) The law of conservation of matter

Question 33

According to Avogadro's hypothesis a liter of oxygen (O₂) will react with _____ liter/s of carbon monoxide (CO) to give two liters of CO₂.

Question 34

The volume of a particular substance is an _____ property of the substance.

Question 35

The extraction of metal from ores is called _____.

Question 36

A gas contains carbon and hydrogen in the ratio 1:0.33 by mass, another gas in the series has carbon and hydrogen in the ratio 1:0.25 by mass. If the first gas was found to be methane (CH₄), then the second gas will be _____.

A) CH₂
B) C₂H₆
C) C₂H₄
D) C₂H₂
E) C₄H₃

Question 37

Compounds are indivisible particles.

Question 38

In Rutherford's experiment α particles aimed directly at the nuclei of gold atoms were deflected by the greatest angle.

Question 39

Of all the subatomic particles, electrons have the lowest mass-to-charge ratio.

Question 40

The major constituents of air are nitrogen (78%), oxygen (21%), carbon dioxide (0.5%), and inert gases. The number of particles present in one volume of air is _____ the number of particles in one volume of pure oxygen.

A) equal to
B) four times greater than
C) 79 times greater than
D) 21% lesser than
E) one fourth

Question 41

Boron occurs naturally in two isotopes ¹⁰B and ¹¹B. The standard atomic mass of Boron is 10.811. What are the percentage abundances of ¹⁰B and ¹¹B? (Given: exact mass of ¹⁰B = 10.01294 amu and ¹¹B = 11.00931 amu)

A) 50% and 50%
B) 60% and 40%
C) 70% and 30%
D) 90% and 10%
E) 20% and 80%

Question 42

Atoms that have the same number of protons but different numbers of neutrons are called _____.

A) isomers
B) epimers
C) isotopes
D) enantiomers
E) diastereomers

Question 43

Which of the following types of radiation has a positive charge?

A) Alpha
B) Cathode
C) Gamma
D) Beta
E) X

Question 44

Scientists can measure relative atomic masses very accurately, however, using an instrument called a _____.

Question 45

_____ rays have no charge, so they are not deflected by electric or magnetic fields.

Question 46

K is the symbol for _____.

Question 47

Explain how the atomic mass for an element with two or more isotopes is calculated with an example.

Question 48

_____ rays are emitted when a high voltage is applied to a gas at low pressure contained in a sealed tube.

A) Alpha
B) Cathode
C) Gamma
D) Beta
E) X

Question 49

Tritium is an isotope of hydrogen with a mass number of 3. Which of the following accurately represents tritium?

A) ${ } _ { 1 } ^ { 1 } \mathrm { H }$
B) ${ } _ { 1 } ^ { 2 } \mathrm { H }$
C) ${ } _ { 1 } ^ { 3 } \mathrm { H }$
D) ${ } _ { 2 } ^ { 1 } \mathrm { H }$
E) ${ } _ { 3 } ^ { 1 } \mathrm { H }$

Question 50

In Rutherford's gold foil experiments, the observation of particles being reflected back directly was due to:

A) alpha particles being deflected off orbiting electrons in gold atoms.
B) alpha particles being deflected off neutrons scattered in gold atoms.
C) alpha particles causing the disintegration of the nuclei of the gold atoms.
D) alpha particles being deflected off protons present in the gold atoms nuclei.
E) alpha particles being deflected off dense electron clouds surrounding the nuclei.

Question 51

List out the properties of protons, neutrons, and electrons?

Question 52

The symbol for sodium is Si.

Question 53

Explain the principle behind the working of a mass spectrometer.

Question 54

Marie Curie coined the term _____ to describe the spontaneous emission of energy rays by matter.

Question 55

_____ rays can be stopped by a sheet of paper.

A) Alpha
B) Cathode
C) Gamma
D) Beta
E) X

Question 56

Most non-metal solids are lustrous.

Question 57

Atomic number of an element is defined as the number of:

A) electrons in the nucleus of an atom of the element.
B) neutrons in the nucleus of an atom of the element.
C) protons and neutrons in an atom of the element.
D) neutrons and electrons in an atom of element.
E) protons in the nucleus of an atom of the element.

Question 58

A mass spectrometer measures the _____ of an atom.

A) mass number
B) absolute atomic mass
C) absolute atomic number
D) relative atomic mass
E) relative atomic number

Question 59

An alpha particle consists off:

A) two electrons and a neutron.
B) two electrons and a proton.
C) two neutrons and two protons.
D) two neutrons and two electrons.
E) two neutrons, a proton and a neutron.

Question 60

_____ is the only atom whose exact atomic mass is equal to its mass number.

A) (¹H)
B) (¹⁶O)
C) (⁹Na)
D) (¹²C)
E) (³He)

Question 61

Write a note on alkali metals and their applications.

Question 62

Elements in the periodic table are stacked in such a way that elements with similar chemical properties form vertical columns, called _____.

Question 63

Which of the following elements is an essential component of the human diet?

A) Copper
B) Silver
C) Aurum
D) Cadmium
E) Germanium

Question 64

Metals are _____, meaning they can be hammered or pressed into thin sheets or foils.

Question 65

Elements of group 1 of the periodic table are known as the _____.

Question 66

Which of the following elements is classified as a halogen?

A) Copper
B) Lithium
C) Sulfur
D) Astatine
E) Krypton

Question 67

Which of the following elements is classified as an alkali metal?

A) Copper
B) Chlorine
C) Cesium
D) Chromium
E) Cadmium

Question 68

Which of the following periods does not contain any essential elements?

A) First
B) Second
C) Fourth
D) Fifth
E) Sixth

Question 69

Which of the following elements belong to the lanthanide series?

A) Boron
B) Neodymium
C) Aurum
D) Aluminum
E) Tin

Question 70

Which of the following group of elements belong to the same period?

A) hydrogen, fluorine, and neon
B) lithium, sodium, and potassium
C) potassium, titanium, and astatine
D) beryllium, carbon, and sulfur
E) cesium, osmium, and argentinum

Question 71

Which of the following is a property associated with noble gases?

A) Lustrous nature
B) Malleability
C) Ductile nature
D) Inertness
E) Salt formation

Question 72

Trace elements are present in very small amounts, ranging from a few grams to a few milligrams in an adult human.

Question 73

Which of the following is a trace element required in the human diet?

A) Lead
B) Sodium
C) Potassium
D) Sulfur
E) Carbon

Question 74

Which of the following elements is a bulk element?

A) Sulfur
B) Calcium
C) Zinc
D) Chlorine
E) Sodium

Question 75

Potassium, nickel and neon are all members of the same period in the periodic table.

Question 76

Magnesium, calcium, and strontium are all alkali metals.

Question 77

Rubidium and strontium are examples of essential trace elements.

Question 78

Halogens react readily with metals to form salts.

Question 79

Distinguish metals from nonmetals.

Question 80

Based on the position in the periodic table, which of the following is classified as a non metal?

A) Boron
B) Lithium
C) Vanadium
D) Aluminum
E) Tin