Module 1: Properties and Structure of Matter Practice Flashcards

Comprehensive fill-in-the-blank practice flashcards covering Module 1: Properties and Structure of Matter, including mixtures, atomic theory, radioactivity, periodicity, and bonding.

A __________ substance has a fixed composition and fixed properties, such as elements and compounds.

pure

The simplest pure substances consisting of only one type of atom are called __________.

Elements

Pure substances composed of two or more elements chemically bonded together in a fixed number are known as __________.

compounds

A __________ mixture is one where the components are not evenly distributed, such as muddy water.

Heterogeneous

In a __________ mixture, such as oxygen in air, each component is evenly distributed.

Homogeneous

The __________ particle of an element that is still recognisable as that element is an atom.

smallest

Waiters and scientists distinguish between atoms by noting that all atoms of a specific __________ are identical.

element

A __________ of an element, such as $H_2$, consists of the same atoms stuck together.

molecule

Charged particles are called __________, with cations being positive and anions being negative.

Ions

The __________ of an inorganic substance is now regulated by IUPAC naming conventions.

nomenclature

A mixture contains various substances that are not __________ bonded.

chemically

Differences in __________ properties, such as magnetism or particle size, are used to separate substances in a mixture.

physical

The property exploited to separate a mixture of salt and sand using water is __________ in water.

solubility

Separation based on __________ size involves techniques like filtration and sieving.

particle

The process of __________ and crystallisation is used to separate a dissolved solid from a liquid.

evaporation

A big difference in __________ points is required to use simple distillation for separation.

boiling

The separation technique __________ distillation is used for mixtures of liquids with significant but small differences in boiling points.

fractional

Separation based on __________ involves sedimentation, decanting, and centrifugation.

density

A __________ funnel is used to separate immiscible liquids with different densities.

separating

The substance that drips through the filter paper during filtration is called the __________.

filtrate

The substance that stays in the filter paper during filtration is called the __________.

residue

Fractional distillation is used to separate __________ into aviation spirit, petroleum, and other components.

crude oil

To obtain pure oxygen and nitrogen from air, the gases must first be cooled to turn them into __________.

liquids

Chromatography works on the principle that different components __________ or cling to the surface of a substance differently.

adsorb

The technique of __________ is used in air to separate materials of different densities, similar to winnowing.

Floatation

Determining what substances are present in a sample is called __________ analysis.

Qualitative

Determining how much of each substance is present in a sample is called __________ analysis.

Quantitative

A method of quantitative analysis that involves the measurement of masses is __________ analysis.

Gravimetric

The first step in gravimetric analysis is to separate components using __________ separation techniques.

physical

The percentage composition of a component in a mixture is calculated as (weight of component / total weight) $\times 100$. This is expressed as __________ %w/w.

percentage

The sum of the atomic masses of all the atoms in a formula is called the formula mass or __________ mass.

molecular

Formula mass is expressed in units of __________.

$$g/mol$$

The atomic mass of Sodium ($Na$) is approximately __________ according to the provided periodic table snippet.

$$22.99$$

The atomic weight of Chlorine ($Cl$) is approximately __________.

$$35.45$$

To determine the percentage of Sodium in Table Salt ($NaCl$), you divide the atomic mass of $Na$ by the total mass of $NaCl$ ($58.44$) and multiply by __________.

$$100$$

The elements on the __________ of the periodic table, excluding Hydrogen, have more distinctly metallic properties.

left

Elements that have features of both metals and non-metals are called __________ or metalloids.

semi-metals

__________ is the only metal that is a liquid at room temperature.

Mercury

Most non-metals are poor conductors of electricity and heat and are usually __________ when solid.

brittle

Carbon in the form of __________ is classified as a semi-metal/metalloid because it conducts electricity.

graphite

Elements in the same vertical column group have similar __________ properties because they have the same number of valence electrons.

chemical

The Roman numerals used in naming transition metal compounds, like Iron (II) chloride, indicate the __________ of the metal.

valency

Polyatomic ions like sulfate ($SO_4^{2-}$) and carbonate ($CO_3^{2-}$) must be __________ for balanced equation writing.

memorised

In a balanced chemical equation, the __________ on the left of the arrow must equal the products on the right.

reactants

The 'pop test' confirms the presence of __________ gas.

hydrogen

The 'limewater test' confirms the presence of __________ gas.

carbon dioxide

The 'glowing splint test' confirms the presence of __________ gas.

oxygen

In a neutral atom, the atomic number equals the number of __________ and the number of electrons.

protons

The __________ number is the sum of the number of protons and the number of neutrons.

mass

Atoms of the same element with the same number of protons but different numbers of neutrons are called __________.

isotopes

Isotopes are named by their __________ number, such as Chlorine-35 and Chlorine-37.

mass

The center of an atom made of a small, dense nucleus makes up most of the __________ of the atom.

mass

Isotopes that do not emit radiation are described as __________.

stable

The weighted average of the relative atomic masses of all the isotopes of an element is the __________ atomic mass.

relative

Relative atomic mass is calculated on the scale of the isotope __________.

$$^{12}C$$

All elements with an atomic number greater than __________ are unstable and radioactive.

83

An __________ particle consists of 2 protons and 2 neutrons and is identical to a Helium nucleus.

alpha

A __________ particle is a high-energy electron emitted from the nucleus.

beta

__________ radiation is high-energy electromagnetic radiation with no mass or charge.

Gamma

In the zone of stability graph, stable nuclei for light elements tend to have a neutron-to-proton ratio close to __________.

1

The time required for half of the atoms in a given radioactive sample to decay is called the __________.

half-life

The radioisotope __________-131 is used in thyroid disease diagnosis and treatment.

iodine

The radioisotope __________-241 is used in household smoke detectors.

americium

Bohr proposed that electrons exist in discrete __________ levels.

energy

The arrangement of electrons in an atom is known as its electronic __________.

configuration

Outer electrons that are responsible for the reactivity of an element are called __________ electrons.

valence

The maximum number of electrons an energy level $n$ can accommodate is given by the rule __________.

$$2n^2$$

Elements in the same __________ have the same number of valence electrons.

group

When an electron falls from an excited state to its __________ state, it releases energy as electromagnetic radiation.

ground

Characteristic colours produced in a __________ test are a result of specific electron transitions in cations.

flame

Schrodinger’s model proposed that electrons behave as __________ around the nucleus.

waves

In quantum mechanics, the 3-D space around the nucleus where an electron is likely to be found is an __________.

orbital

Subshells in the quantum model are labeled with the letters __________, p, d, and f.

s

According to the __________ Principle, lowest energy orbitals are filled first.

Aufbau

The __________ Exclusion Principle states that each orbital can hold a maximum of two electrons with opposite spins.

Pauli

__________ Rule states that orbitals in a subshell are each filled with one electron before any orbital is filled with a second.

Hund's

__________ is the term used to describe general patterns across the Periodic Table like atomic radius and electronegativity.

Periodicity

Atomic __________ refers to the distance from the nucleus to the valence electrons.

radius

Across a period from left to right, atomic radius __________.

decreases

Down a group, atomic radius __________ because the number of electron shells increases.

increases

The amount of energy required to remove the first electron from a gaseous atom is the first __________ energy.

ionisation

Ionisation energy __________ across a period as the atomic radius decreases.

increases

__________ is a measure of the electron-attracting power of an element when it forms compounds.

Electronegativity

The most electronegative element on the Pauling scale is __________.

fluorine

Metal reactivity __________ down a group because valence electrons are further from the nucleus and easier to remove.

increases

Strong electrostatic forces of attraction between oppositely charged ions result in __________ bonding.

ionic

Ionic compounds form a 3-D __________ structure.

lattice

A __________ bond occurs when a pair of electrons is shared between two non-metal atoms.

covalent

The theory used to predict the geometry of molecules based on electron pair repulsion is __________.

VSEPR

Molecules held together by weak intermolecular forces but strong intramolecular bonds are __________ molecular compounds.

covalent

Diamond and Silicon Dioxide are examples of covalent __________ solids.

network

Different forms of the same element in the same physical state, like diamond and graphite, are called __________.

allotropes

__________ bonding is the attraction between metal cations and a 'sea' of delocalised electrons.

Metallic

Covalent bonds in which electrons are shared unequally due to electronegativity differences are called __________ bonds.

polar

A __________ is a pair of equal and opposite charges separated in space across a bond.

dipole

Forces between molecules, such as dispersion forces or hydrogen bonds, are called __________ forces.

intermolecular

__________ forces are weak, temporary dipoles caused by the constant movement of electrons.

Dispersion

A __________ bond is a strong dipole-dipole force occurring when H is bonded to N, O, or F.

hydrogen

The arrangement of water molecules in ice creates an open structure that makes it __________ dense than liquid water.

less

A molecule with 4 bonding pairs and 0 lone pairs around a central atom has a __________ shape.

tetrahedral