Science Basics: Solutions and the Scientific Method

heating up the solution and cooling it down slowly more solute can be dissolved than normally is possible. When it cools solute will precipitate out of the solution.

systematic means of exploring the world around you.

is what you decide about an observation. attempt to explain or interpret observations based on the evidence and/or our experience.

is an educated guess about a future event. may or may not happen, but it should be logical.

Usually, a hypothesis can be supported or refuted through___ or more ___

What one thing will I change on purpose? Scientists call this the ___(manipulated).

How will I know if the one thing changed on purpose made any difference? Scientists call this the ___

What things will need to keep exactly the same? ___

is the group in an experiment that does not receive the variable you are testing. A ___ is something used as a standard of comparison for checking the results of an experiment.

is the group that receives the variable being tested in an experiment.

is the group in an experiment that does not receive the variable you are testing.

is something used as a standard of comparison for checking the results of an experiment.

is something that is kept the same in an experiment.

is a number or feature that is changeable that can have lots of different possible values.

Term for: Data are pieces of information collected before, during, and after an experiment. It is important to keep detailed notes and to record all data collected throughout the scientific inquiry process So that it can be analyzed to determine results and referenced to support the conclusions.

is based on numerical data, which can be analyzed using statistics. This type of research focuses on pinpointing what, where, when, how often and how long social phenomena occur.

is based on data that cannot be measured or counted, but can be collected and interpreted through observation.

when one increases so does the other, or as one decreases so does the other.

if when one increases the other decreases, or as one decreases the other increases.

like predictive weather (model) or atom (model)

like a model volcano

Term for: Scientists make sure that they collect accurate data so their results will be trustworthy. Unfortunately, not all data in science experiments is of the same quality. Some people are better at measuring things than others, and sometimes there can be issues that cause all your data to be off by a certain amount.

___of data tells you how close to being correct your data is.

___, or precision, of data tells you how close together your measurements are and is as exact as possible.

is a statement that summarizes a collection of observations or results from experiments. are always true under the same conditions and therefore can be used to make predictions.

___, or model, is also based on a set of hypotheses. Unlike a law, however, a ___ describes and explains why a natural phenomenon occurs.

In science, __explain reality well and are generally accepted as truth.

__are based on information from many different areas of study.

ring with screw fasteners, fastens to ring stand as support for apparatus (such as a beaker)

Stand in with clamps and rings may be placed to hold an apperatus

to hold apparatus (test-tube) may be fastened to the ring stand

protects eyes from flying objects and chemical splashes

simple portable appliance for heating

heavy porcelain dish with grinder - to grind chemicals to a powder

to transfer solid chemicals in weighing

rack to hold test tubes in an upright position

porcelain dish used as a container for small amounts of liquid being evaporated

curved glass used as a beaker cover or used in evaporating very small amounts of liquid

used to hold filter paper; may be used to ease in pouring

Glass tip with a rubber bulb; used to transfer small amounts of liquids

used to pick up or hold small objects

two main parts: bulb and stem. Used to dispense small quantities of liquids

Used to transport or scrape out solid chemicals from their containers

used when moving test tubes too warm to touch

used for mixing and heating chemicals, made of pyrex, not for measuring exact volumes

used to mesure liquid volumes more accurately than a beaker

used for heating, mixing, and storing liquids, has narrow neck to prevent splashes

narrow glass cylinders used for mixing, heating, and storing small amounts of chemicals

glass rods used to stir mixtures when metal can't be used

hollow metal barrel that mixes gas and air to create a flame

ceramic that can withstand high temperatures, used to heat solids

tool used for handling hot objects

used for cleaning a test tube

used to measure the mass of substances accurately (not depending on pull of gravity)

glass tube with mercury or colored alcohol used to measure temperatures

used to support crucibles on a ring stand

scale for weighing, depends on pull of gravity

can be used to support beaker when used with an iron ring

glass container usually holds denatured alcohol, used for heating chemicals and equipment using alcohol

gives you a means to evaluate how far apart your prediction and measured values are.

Percent error is calculated as ___

__system of measurements is based on the metric system which uses seven base units.

SI Measurements

is used as a short hand way to represent either very large or small numbers.

The first number is called the__. It must be greater than or equal to 1 and less than 10.

The second number is called the__. It must always be 10 in scientific notation. The base number 10 is always written in exponent form.

are the number of figures in an answer that are known with certainty.

are used to express how precision of a measurement.

is defined as the ratio between mass and volume or mass per unit volume. It is a measure of how much stuff an object has in a unit volume (cubic meter or cubic centimeter).

is a measure of how much stuff an object contains

is the measure of how much space an object occupies in three-dimensional space.

we can use ___to find an object's volume (think Archimedes)

the downward or upward curve at the surface of a liquid in a container, occurs because of surface tension in the liquid and must be read at eye level.

For ___, the correct volume will be read at the bottom of the curve.

density equasion

are formed when elements combine together in a chemical bond.

has completely different properties than the elements that make it up.

_____ Compounds form into *ions* and are made from positive ions and negative ions and have strong chemical bonds. Having strong chemical bonds means that their melting and boiling points are very high.

___ compounds form *molecules*: chemical bonds are much weaker than ionic compounds, melting and boiling points are much lower than ionic compounds. Examples: sugar (C12 H22 011), water (H20), dihydrogen sulfide (H2S).

is sum of the atomic masses of the elements in its chemical formula. (amu)

the ___ of any substance, be it element or compound, is defined as the mass of 1 mole of the substance. (g/mol)

are made of different substances that combine together only physically.

retains the properties of the substances that make it up.

Mixtures can be separated by normal physical means such as ___ (give examples)

What holds atoms together in a chemical bond?

A bond formed between metals that lose electrons [positive ions] and nonmetals that gain electrons [negative ions]. Valence electrons are transferred from positive ions to negative ions

lonic compounds form into strong network solids called crystalline structures with high melting points and conduct electricity when melted or dissolved into water, called ___

____ bonding forms molecules with low melting and do not conduct electricity when dissolved in water (NON electrolytes).

unequal sharing of valence electrons

equal sharing of valence

____bonding can share either 1 pair (single bond-weak), 2 pairs (double bond-stronger), or 3 pairs (triple bond- strongest) of valence electrons.

___ are molecules composed of only two atoms. There are seven elements that occur naturally hydrogen (H2), nitrogen (N2), oxygen (O2), fluorine (F2), and chlorine (Cl2), iodine (I2) and bromine (Br2)

_____ bonds between atoms of the same metal, usually transition metals.

___ bonds Formed by the attraction between positively charged metal ions and the "sea of electrons" that surrounds them.

___is why metals conduct heat and electricity and are so malleable and ductile.

Groups of atoms that are bonded together covalently that act like a single ion that can a have either a (+) or a (-) charge.

The charge of a ___applies to the whole group of atoms that makes up the _____. Examples of ___and their charges (see the back of the periodic table): OH (Hydroxide ion), CO32 (Carbonate ion), NO 3* (Nitrate ion), SO 42 (Sulfate ion), PO43 (Phosphate ion)

The partial positive and negative charges in the molecule create a __

is a combination of two or more substances in which each substance retains its own chemical properties.

the state of a material that consists solely of a single element or compound

any material that is made up of only one type of atom

a substance containing atoms of two or more different elements chemically bonded together.

the state of a material that is a mixture of more than one element or compound.

are not the same throughout

heterogeneous mixture that can look uniform only when it is stirred or shaken but separates into different layers when it is no longer being agitated.

heterogeneous mixture whose particles are much smaller than in a suspension, will NOT settle out of the substance

two liquids that will separate when left alone are heterogeneous mixtures. Examples include oil & water, or oil and vinegar salad dressing

mixtures that not only look uniform throughout, but really are uniform and do not separate when left alone.

are homogeneous mixtures; one substance is DISSOLVED in another.

is the part that gets dissolved.

is the part that does the dissolving

Liquid-Liquid solutions are called ___when a liquid solute dissolves into a liquid solvent. Examples include methyl or ethyl alcohol dissolving into water, or acetic acid dissolving into water to form vinegar.

Solid-Solid solutions,__, a mixture of two or more metallic elements.

separating the liquids in the mixture b/c each has a different boiling point.

used to separate colors of dyes in ink.

states that a solute dissolve into a solvent because of the motion of the molecules of both solute & solvent.

If a substance will dissolve into another it is ___

If a substance will NOT dissolve into another it is ___

can dissolve more solute under the same conditions of temperature and pressure

has dissolved as much solute as possible under the given conditions of temperature and pressure

The Universal Solvent (Polar Molecule)

the relative quantity of solute that is dissolved into a solvent, concentration can be either weak or strong.

are weak solutions with very little solute dissolved

a strong solution that has a large quantity of solute dissolved.

is a very precise, mathematical way of measuring the concentration of a solution.

Molarity (M) equation

Si base unit that describes amount of a substance (Avogadro's number 6.02 X 1023 particles) - The number of particles - 6.02 x 1023 - contained in 1 mole of anything.

(be able to interpret data)

are the substances that undergoes a chemical change and the products are the substances that is formed as a result of the chemical change.

use the chemical formulas of elements and compounds to describe what occurs during a chemical reaction. (Shorter and easier way to show chemical reactions.)

are the new substances that are created from the reactants reacting w/each other and are on the right side of the arrow.

are the substances that you start with, they are always written on the LEFT side of the chemical equation. The reactants react with each other to make the products.

is neither created nor destroyed during a chemical reaction; atoms merely rearrange, without any apparent loss or gain of mass, to form new molecules.

two or more reactants combine to form a single more complex product.

a reaction in which one reactant compound breaks into two or more products. The "electrolysis" of water, the digestion of foods, the "cracking" of crude oil are examples.

a reaction in which a hydrocarbon compound and oxygen are reactants that burn. If there is an adequate supply of oxygen, then CO2 and H20 are the products.

atoms of one element take the place of atoms of another element in a compound. There is always a compound and an element on the left side of the reaction (reactants) and an element and a compound on the right side (products) of the chemical equation. The more reactive element will take the place of a less reactive one.

a reaction in which two reactant compounds exchange their positive ions and produce two different compounds as products.

can be derived from the coefficients in a balanced chemical equation.

is energy that is present within atoms and molecules.

(also known as the First Law of Thermodynamics) applies to all chemical reactions- energy is transferred and changed from one form into another in a chemical reaction, but energy cannot be created or destroyed.

must be added in order to break chemical bonds. Usually in the form of heat, light, sound, or electricity.

chemical reactions that release energy from the chemical energy of the reactants. The reactants have a higher potential energy than the products, and a ΔH that is negative. Burning, explosions, digestion, respiration, bioluminescence are all exothermic reactions.

chemical reactions that absorb energy from their surroundings. The products have higher potential energy than the reactants, and the ΔH is positive. Photography and photosynthesis are examples of endothermic reactions.

what system of mesurment was made for scientists

Name this model

Name this model

Name this model

Name this model

Name this model

Name this model

first emblems of a binary compound

second emblems of a binary compound

tells you how many electrons an atom must gain, lose, or share to become stable.

Can be derived from the coefficient in a balanced chemical equation

BAAD Acronym

Substances that contain hydrogen ions (H+) and produce hydronium ions (H3O+) (Acids or Bases)

Taste sour(Acids or Bases)

turn Indicator paper (litmus paper) from blue to red.(Acids or Bases)

____ become electrolytes when dissolved in water(Acids or Bases)

___ have a pH of less than 7(Acids or Bases)

Substances that contain hydroxide ions (OH-) and produce hydroxide ions (OH-)(Acids or Bases)

taste bitter and feel slippery(Acids or Bases)

will turn red litmus paper blue(Acids or Bases)

good conductors of electricity(Acids or Bases)

pH of greater than 7(Acids or Bases)

A chemical reaction in which H3O+ ions from an acid and OH-ions from a base react to produce neutral substances (water and salt)

change color in presence of an acid or base

Is an educated guess, based on observation. It's a prediction of cause and effect

The reproducibility, or ____, of data tells you how close together your measurements are and is as exact as possible.

___is the greatest quantity of a solute that will dissolve in a given amount of solvent at a given temperature.

Measured in grams of solvent / 100g of solvent.