Science Midterm Exam

An exact report of what your senses tell you.

Accurate Observation

The variable that is manipulated or changed by the experimenter ("I" control this variable). Where is the data found on the graph?

Independent variable. The x-axis

Avoids opinions (or bias) based on specific points of view.

Object observation

Using one or more of your senses (sight, touch, hearing, taste, and smell) to gather information about our world

Observing

What do particles in a liquid look like?

They are close together (attracted to each other) but are farther apart than solids. They slide freely past one another but can move around.

The measurement how much force is acting on an object because of gravity.

Weight

Molecules are made of ____ and all _____ in our world are made of very few types of atoms.

atoms/substances

Tools for measuring: Volume

beaker, graduated cylinder, flask

If the gas from the bath bomb puts out a flame above it, that means it is ____ dense than the air around it.

less

If the gas from the bath bomb puts out a flame below it, that means it is ____ dense than the air around it.

more

What is an example of a independent variable and a dependent variable?

ndependent variable, the type of pop. Dependent variable, the blood sugar levels

When a ____ substance are produced from ___ substances, some of the ____ that make up the original substances break ____ and/or ____ to make new types of particles.

new/old/particles/apart/join.

New substance is something ___ forming in the _____ but there is no ____ in mass and therefore no new _____ is formed.

new/system/change/matter.

All matter is made up of what?

particles that are to small to be seen.

In a chemical reaction, the particles that make up can be _______ to form ___ molecules to make new ______.

rearranged/new/substances

The process of making observations and inferences are kept...

separate

Tools for measuring: Weight

spring scale

The factors that can affect the results of an experiment

variable

Why do different substances have different odors and how do we detect them?

As you breathe in, the molecules enter the nostril to the back of the nose to the membrane called olfactory epithelium. There, they bond to odor-receptor cells. They send the signals to the brain. The brain transmits the signal to the rest of the brain. Which analyzes what Oder the molecules are linked to. The type of molecule will detect the different scents.

Which ingredients, when combined, did we discover were responsible for producing the bath bomb bubbles?

Baking soda in water with sugar-free lemonade, baking soda in water with citric acid, baking soda with water with sugar-based lemonade.

An organized way to write a scientific explanation

CER model

A statement about the results of an investigation or experiment

Claim

A variable in an experiment which does NOT change

Constant variable

Sample that is treated like the other experimental groups except that the independent variable is not applied to it. Used to provide a comparison.

Control Group

What was the result of the open system of crushing the bath bomb with water?

Decreased in mass by 1g

What is the equation for density?

Density = mass/volume (g/mL)

The quantity that responds to the changes in the independent variable. The value depends on the changes in the independent variable. The data collected during the investigation. Where is the data found on the graph?

Dependent variable. The y-axis.

Tools for measuring: Mass

Electrical balance, triple beam balance.

Scientific data to support the claim

Evidence

Sample that has the independent variable applied to it.

Experimental Group

What was the result of putting the bath bomb in water in a ziplock bag?

Filled up with some air, didn't change in mass.

How a substance interacts with fire.

Flammability

Describes a material that does not dissolve in something else.

Insoluble

What happened to the water molecules when electricity was ran through it?

It separated into 2 different substances. 2H₂O --> 2H₂+O₂

What is the key sentence for reading metric conversions?

Kids (kilo) hate (hecto) drinking (deci) bad (base units) chocolate (centi) milk (milli) or King (kilo) Henry (hecto) dances (deci) badly (base units) during (deci) cold (centi) months (milli)

The amount of matter in an object and it does not change. Measured in grams.

Mass

Tools for measuring: Distance

Meter stick, ruler, tape measure.

Did any individual ingredient in a bath bomb produce gas/bubbles when mixed with water?

No

What was the result of crushing the bath bomb in a ziplock bag without water?

No change in mass, bag didn't fill with gas.

What was the result of crushing the bath bomb in a open system without water?

No change in mass, no gas trapped inside the bath bomb

How can a new substance be produced and the total mass for the closed system not change?

No substance from the reaction can escape from the closed system and no substance around it can enter either.

What are some possible ways of what is happening when new substances are made in the bath bomb?

Particles join together, break apart and join together in a new way, citric acid particles break apart and make a new gas, baking soda particles break apart and make a new gas, or water particles break apart and make a new gas.

Descriptives that DO NOT use numbers (colors, smells, texture, taste, sound, ect.)

Qualitative Observation

Descriptives that INCLUDES numbers.

Quantitative Observations

Ties together the claim and evidence

Reasoning

Describes a material that can dissolve in a particular substance.

Soluble

Made of one type of material throughout.

Substance

Where do you read from on a meniscus?

The bottom

How did the properties of flammability and density to test gasses and determine the identity of the unknown bath bomb gas?

The flammability told us that the bath bomb gas is less dense than 1.160-1.161 (normal air) so the options it could only be is nitrogen, carbon dioxide, or argon.

What do particles in a solid look like?

They are close together, vibrate in place, and do not move around - fixed in place.

What do particles in a gas look like?

They are far apart from each other and they move freely in all directions - bumping in the walls of their container and into each other.

Property

a characteristic of a substance that does not chage.

How much matter is in a certain space.

density

When a solid breaks apart into particles too small to be seen and completely in the liquid.

dissolve

New matter is a matter that ____ the system from _____ of the system. Because all matter has _____ and _____, we should see a change in ____ as ____ ____ enters the system.

enters/outside/mass/volume/mass/new matter

Any information that is gathered from making observations is called...

evidence or data

observations are usually followed by attempted explanations, which are also called...

inferences

Matter has ___ and ___. It takes up ___

mass/volume/space

"stuff" that makes up the universe. Has mass and volume.

matter

Solid, Liquid, Gases are forms of

matter

In a closed system no ____ can get ___ or ___, so the ____ stays the same.

matter/in/out/mass

In a open system, _____ can get ___ or ____ so the ____ does change.

matter/in/out/mass

A blend of two or more substances

mixture

The same substance is made up of the same type of ____ throughout. The number of types, and _____ of atoms in molecules make up a substance are ____ to that substance.

molecules/arrangement/unique