Science S1 Exam

What are the metric units of measurement for distance?

Meter

What are the metric units of measurement for mass?

Gram

What are the metric units of measurement for volume

Liter

What is the Law of Conservation of Matter?

The principle stating that matter cannot be created or destroyed in a closed system, only transformed.

What are some physical properties of matter?

Volume, density, color, and state (solid, liquid, gas) are properties that can be observed or measured without changing the substance's chemical identity.

What are some chemical properties of matter?

Reactivity, flammability, pH, and the ability to undergo a chemical change, describes how a substance interacts with other substances.

What is a pure substance?

A material that has a uniform and definite composition, consisting of only one type of particle. Can be elements or compounds.

What are elements?

Substances that cannot be broken down into simpler substances by chemical means, consisting of only one type of atom.

Examples of elements?

Hydrogen, Oxygen, Carbon, Gold

What are compounds?

Substances formed when two or more elements chemically combine in fixed proportions, having unique properties distinct from the individual elements.

Examples of compounds?

Water, Sodium Chloride, Carbon Dioxide, Methane

How are compounds formed?

Compounds are formed through chemical reactions when two or more elements bond together in fixed ratios, resulting in a substance with properties different from those of the individual elements.

What is a mixture?

A combination of two or more substances that are not chemically bonded and retain their individual properties.

Homogeneous mixture

A mixture that has a uniform composition and appearance throughout, with components that are evenly distributed.

Heterogeneous mixture

A mixture that has a non-uniform composition and appearance, where the individual components can be easily distinguished and separated.

What are solutions?

Solutions are homogeneous mixtures where one substance is dissolved in another

What are suspensions?

Suspensions are heterogeneous mixtures in which solid particles are dispersed in a liquid or gas but are not fully dissolved, allowing the particles to settle over time.

What is a colloid?

a heterogeneous mixture where small particles are distributed evenly through another substance, but are not large enough to settle out or be easily separated.

What are some examples of colloids?

milk, fog, and mayonnaise

What is a solute?

A substance that is dissolved in a solution

What is a solvent?

A substance that dissolves a solute in a solution.

What is a physical change?

A change that alters the form or appearance of a substance but does not change its chemical composition.

What are examples of a physical change?

Melting ice, boiling water, and dissolving sugar in water.

What is a chemical change?

A change that results in the formation of one or more new substances with different chemical properties and compositions.

What are examples of a chemical change?

Examples include rusting iron, burning wood, and cooking an egg.

What is the Law of Conservation of Matter?

The principle stating that matter cannot be created or destroyed in a chemical reaction, only transformed.

What is an examples of each state of matter?

Solid, liquid, gas,

In terms of shape & volume, what does each state of matter have?

solids have a definite shape and volume, liquids have a definite volume but take the shape of their container, and gases have neither a definite shape nor volume.

What happens during the phase change freezing?

a liquid turns into a solid as its temperature decreases and its particles lose energy, causing them to arrange into a fixed structure.

What happens during the phase change melting?

a solid turns into a liquid as its temperature increases and its particles gain energy, allowing them to move more freely.

What happens during the phase change evaporation?

a liquid turns into a gas as its temperature increases and its particles gain enough energy to overcome intermolecular forces.

What happens during the phase change condensation?

A gas turns into a liquid as its temperature decreases and its particles lose energy, causing them to come closer together.

What is a Freezing Point?

The temperature at which it freezes to solid at normal atmospheric pressure

What is a boiling point?

The temp at which a liquid boils at normal atmospheric pressure

Why is salt added to ice?

Reduce melting point and speed up melting of ice.

What are some environmental impacts of deicing?

It can pollute lakes and runoff and harm wildlife

How do scientific models help us?

help improve explanations, generate discussion, make predictions, and provide visual representations of abstract concepts

Why and when do scientific models change?

may change over time as a result of additional research or experimentation.

What are atoms?

smallest unit of matter

What are elements?

substances that cannot be broken down into other substances

What are molecules?

two or more atoms bonded together by chemical bonds and is a pure substance

What are diatomic molecules?

A pair of elemental molecules that contain exactly 2 atoms of the same element.

What are elemental molecules?

molecules containing two or more atoms of the same element

What are molecular compounds?

compounds formed from two or more nonmetals

How can you determine the amount of an element in a molecular formula?

Subscript

What are rows called on the Periodic table?

periods

How many periods are on the table?

7 periods

What does the period number tell you for an element?

The amount of rings

What are columns called on the Periodic table?

groups

How many groups are there on the table?

18

What does the group number tell you for an element?

the number of valence electrons

What are subatomic particles?

protons, neutrons, electrons

What is the charge of protons?

positive

What is the charge of neutrons?

neutral (no charge)

What is the charge of electrons?

negative

Where are protons located in an atom?

inside the nucleus

where are neutrons located in an atom?

inside the nucleus

Where are electrons located in an atom?

electron cloud/rings

Why are protons and electrons attracted to each other?

They are oppositely charged. stable atoms have equal amounts

What are valence electrons and where are they located?

electrons in the outermost shell

How many electrons can each ring hold?

1st- 2

Rest- 8

What is the name of group one?

Alkali metals

What is the name of group two?

alkali earth metals

What is the name of groups 3-12?

transition metals

What is the name of groups 13-16?

mixed metals

What is the name of group 17?

Halogens

What is the name of group 18?

Nobel gases

Where are the Lanthanide and Actinide Series located?

detached and mostly created in labs and don't exist naturally

Why is Hydrogen located with group 1?

it has one electron in its valence ring similar to Alkali Metals.

Why is Helium a noble gas with only 2 electrons?

it's valence ring is full, so it's doesn't form chemical bonds at all

What is the basic name for Groups 13-16 and why are they called this?

there is a mixture of different types of elements (metals, metalloids, and nonmetals)

Atomic Number

the number of protons in the nucleus of an atom

Mass Number

the sum of the number of neutrons and protons in an atomic nucleus

What does a subscript tell you for an element?

written just below an element. They tell you how many of that element are bonded in the molecule. If an element has no subscript, it has only 1 of the elements

What is a coefficient?

A number placed in front of a chemical formula in an equation

What is the Law of Conservation of Matter? How is it validated in chemical reactions?

Matter is never created or destroyed. All the atoms present at the start of the reaction are present at the end.

What is a Chemical Reaction?

process that changes one set of chemicals into another set of chemicals

How can you tell if a chemical reaction has occurred?

Change in color, temperature(hot or cold), formation of gas (bubbles), fire (flammability), light production, and new substances are formed.

What is a Chemical Bond and why do atoms form compounds?

A force that holds atoms together, forms compounds through chemical reactions, very strong but can be broken, occurs using valence electrons. Atoms form compounds because they want their valence ring to be filled.

Where are reactants and products located in a chemical formula?

The molecules that react are called reactants(left) and the new substances produced are called products(right).

What does the arrow mean?

to produce or form

Synthesis

combining parts into a whole

Decomposition

A chemical reaction that breaks down compounds into simpler products.

Single Replacement

one element replaces another element in a compound

Double Replacement

a chemical reaction where two elements in different compounds trade places

How can you use the location of an element on the periodic table to determine its bonding?

by determining if it's a metal, non-metal, or metalloid by seeing where it is on the periodic table

What do group numbers tell you for an element?

The properties of the elements, how many valence electrons there are

What is "the staircase," and what does it tell you?

divides the metals and non-metal and elements that touch the staircase (except Al) are metalloids.

What is the role of the Valence Electrons in bonding?

Valence Electrons will be shared, given away, or taken to stabilize the atom. They also help identify characteristics of atoms.

What is the Octet Rule (or Rule of 8)?

Atoms want 8 valence electrons on their valence. Atoms will share, give away, and take Valence Electrons to get eights

What two elements are exceptions to the Octet Rule?

Hydrogen and Helium since they only have one ring, their valence ring is full.

Metallic Bonds

a bond formed by the attraction between positively charged metal ions and the electrons around them

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

What is a delocalized electron?

electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond

Which types of element (metal, non-metal) form metalic bond?

Metal ions

After metallic bond happens, what is the compound called?

Alloy

What happens with the valence electrons in covalent bonds?

They are shared between two or more nonmetals

Which types of element (metal, non-metal) form covalent bond?

Two non-metals