Based on the law of conservation of energy, which statement is correct?

After a hypothesis is proven wrong, scientists often begin by revising the hypothesis, it’s common for scientists to redesign the __________ (question, hypothesis, experiment, conclusion).

Classify the items based on whether they are or are not matter. Check all the examples of matter.

Select the forms of energy in the image.

Select the volume units that are greater than one liter.

Identify the type of energy conversion represented by each picture.

Identify the type of energy conversion represented by each picture.

Identify the type of energy conversion represented by each picture.

Identify the type of energy conversion represented by each picture.

Match the sentences with the steps of the scientific method.

State a hypothesis.

Match the sentences with the steps of the scientific method.

Make an observation.

Match the sentences with the steps of the scientific method.

Analyze the results.

Match the sentences with the steps of the scientific method.

Communicate the results to others.

What two activities are basic to most of science?

Science starts with gathering ________________________ about the natural world.

The stuff that everything is made of is:

The ability to do work is called:

Moving objects have energy of:

SI units to measure volume are:

How many mL are in 3.5 KL?

Convert 70 ounces (Oz) to kilograms

Convert 6000 mL to qt

William finds a piece of pure iron in his garden. After a few days, the iron begins to rust. What are the two types of substances involved in the rusting process of iron?

Iron is a/an________ (compound, element, mixture)

with one kind of atom that combines with oxygen from the air to form rust (iron oxide).

Rust contains two types of atoms, which means it is a_____________. (compound, an element, a mixture)

Type the correct answer in the box. Use numerals instead of words.

Frank has a sample of steel that weighs 80 grams. If the density of his sample of steel is 8 g/cm³, what is the sample’s volume?

The sample’s volume is ____cm³.

Mathew has a filtration kit, which consists of a funnel, a flask, and filter papers. Which of these mixtures can he separate using filtration?

Check all the sentences based on whether they describe the properties of a heterogeneous mixture.

Which unit is commonly used to measure density?

An alloy is made up of two kinds of metals. This alloy is uniform in appearance. How would this material be classified?

An electric iron is used to remove wrinkles from clothing. The electric iron is made of metal. Which property of this substance is most useful for this application?

What is a substance?

Daniel has a sample of pure copper. Its mass is 89.6 grams (g), and its volume is 10 cubic centimeters (cm³). What’s the density of the sample?

Erica is working in the lab. She wants to remove the fine dust particles suspended in a sample of oil. Which method is she most likely to use?

Which of the following property does not describe a compound:

Suspension can be separated by filtration.

Solution is a __________ mixture.

(homogenous, hetergenous, compound)

The mass of an atom is found by adding its protons and _____________.

The electric charge of an atom is found by adding the charges carried by its protons and ___________.

Type the correct answer in each box.

The mass number of iodine is 126, and it’s in the 53rd place in the periodic table. It has __________protons and __________neutrons.

Identify the elements that appear before iron (Fe) in the periodic table.

Mercury is in the 80th position in the periodic table. How many protons does it have?

Mr. Adams asked his students to write the chemical symbol for the element zinc. He wrote the students’ answers on the whiteboard. Which answer is correct?

Sodium (Na) and potassium (K) are in the same group in the periodic table. Sodium is in the 11th position. How many valence electrons does potassium have?

The atomic number of krypton (Kr) is 36, and its mass number is 84. How many neutrons does it have?

What does the subscript in a chemical formula tell you?

a positively charged subatomic particle found in the nucleus of every atom

a subatomic particle that has about the same mass as a proton but does not have an electric charge

the number of protons in an atom’s nucleus

an abbreviation for an element

an electron in the outermost energy level of an atom

a substance that conducts heat and electricity, tends to be shiny, and is used in many industrial applications

an element that in its solid state has properties of both metals and nonmetals

an element that in its solid state is brittle, dull, and a poor conductor of heat and electricity

a group of reactive nonmetal elements found in column 17 of the periodic table

a group of nonreactive nonmetal elements found in column 18 of the periodic table

Select the Noble Gas

Why does a solid change to liquid when heat is added?

Why does ice float on water?

When a perfume bottle is opened, some liquid changes to gas and the fragrance spreads around the room. Which sentence explains this?

An iron nail is made up of particles. What is true about the particles?

Select the correct answer from each drop-down menu.

When a liquid is cooled, the kinetic energy of the particles __________________ , and the matter changes its state to solid.

Select the correct answer from each drop-down menu.

When a liquid is cooled, the force of attraction between the particles ________________ , and the matter changes its state to solid.

Select the correct answer from each drop-down menu.

When a liquid is cooled, the space between the particles ______________.

, and the matter changes its state to solid.

A phase change from liquid to gas is called ...

Is the substance gaining or losing energy?

Are the particles moving faster or slower as time goes on?

What state/phase is the object likely from points A to B?

What is happening to the particles in the substance between points A and B?

What is happening to the particles in the substance between points D and E?

Is the substance gaining or losing energy?

Where on the graph are phase changes taking place?

Identify the arrows that show removal of thermal energy when matter changes state.

Some fuel cells are powered by hydrogen. Scientists are looking into the decomposition of water (H₂O) to make hydrogen fuel with the help of the Sun’s energy.

What challenge do scientists face with this task?

Which chemical reaction shows photosynthesis?

Which of these reactions is a combustion reaction?

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells?

In a given chemical reaction, the energy of the products is less than the energy of the reactants. Which statement is true for this chemical reaction?

A hydrogen fuel cell is more efficient than a combustion reaction because very little of the released energy is released as ______?

When used at home, a fuel cell eliminates the need for _________ because the cell is portable.

In a chemical reaction, activation energy increases __________ of the reactants.

Increasing activation energy causes the particles to collide, which results in the _____________ of new products.

Which chemical reactions are based on whether they absorb energy.

Which chemical reactions are based on whether they release energy.

Arrange the characteristics of the reaction in order from start to finish.

Identify the parts of the energy diagrams.

Part A.

Identify the parts of the energy diagrams.

Part B.

Identify the parts of the energy diagrams.

PartC.

Identify the parts of the energy diagrams.

PartC.

Identify the parts of the energy diagrams.

Part B..

Scientists are looking into the decomposition of water (H₂O --> H₂ + H₂O) to make hydrogen fuel with the help of the Sun’s energy. What challenge do scientists face with this task?

Endothermic reactions ______.

Energy is _________ when bonds form.

Energy is _________ when bonds break.

Energy is needed to break bonds in chemical reactions.

A chemical reaction in which more energy is absorbed than is released is endothermic

Temperature usually _____ in EXOthermic reactions.

Photosynthesis is an _____ reaction.

Which letter corresponds to the activation energy?

The chemical formula for sulfuric acid is H₂SO₄.

In 2H₂SO₄, the number of hydrogen atoms is_____?

The chemical formula for sulfuric acid is H₂SO₄.

In 2H₂SO₄, the number of sulfur atoms is ___?

The chemical formula for sulfuric acid is H₂SO₄.

In 2H₂SO₄, the number of oxygen atoms is _____?

When sodium reacts with chlorine, sodium chloride is produced.

Andrew represented this reaction with this equation:

Na + Cl₂ → 2NaCl

The equation is _____________.

When sodium reacts with chlorine, sodium chloride is produced. Andrew represented this reaction with this equation:

__Na + __Cl₂ →__NaCl

Which set balances the equation?

When butane burns in oxygen, it produces carbon dioxide and water. This reaction is represented in this equation:

2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

How many atoms of carbon (C) on each side of the equation?

When butane burns in oxygen, it produces carbon dioxide and water. This reaction is represented in this equation:

2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

How many atoms of oxygen (O) on each side of the equation?

When butane burns in oxygen, it produces carbon dioxide and water. This reaction is represented in this equation:

2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

How many atoms of hydrogen (H) on each side of the equation?

Iron reacts with oxygen to produce iron oxide (rust). This reaction is represented in an equation as 4Fe + xO₂ → 2Fe₂O₃.

Identify the value of x that will balance the equation.

The chemical formula for artificial sweetener is C₇H₅NO₃S.

Match the elements with the numbers found in one molecule of artificial sweetener.

carbon

The chemical formula for artificial sweetener is C₇H₅NO₃S.

Match the elements with the numbers found in one molecule of artificial sweetener.

hydrogen

The chemical formula for artificial sweetener is C₇H₅NO₃S.

Match the elements with the numbers found in one molecule of artificial sweetener.

sulfur

The chemical formula for artificial sweetener is C₇H₅NO₃S.

Match the elements with the numbers found in one molecule of artificial sweetener.

Oxygen

Which chemical equations are being balanced ?

Calcium carbonate is a compound that is used to make chalk for drawing on rocks or pavement. One molecule has one atom of calcium (Ca), one atom of carbon (C), and three atoms of oxygen (O). Which is the correct way to write the chemical formula for calcium carbonate?

The picture represents sulfur trioxide.

Which statement is true for one molecule of sulfur trioxide?

If blue represents one atom of nitrogen, and   red represents one atom of oxygen, which picture represents 2NO₂?

Sodium bicarbonate is the chemical name for baking soda. Its chemical formula is NaHCO₃. What does the subscript 3 mean?

Samuel adds a teaspoon of salt to a glass of water. He notices that the salt disappears. Samuel takes a sip to discover that the water tastes salty. What kind of change has occurred?

Carbon burns in the presence of oxygen to give carbon dioxide. Which chemical equation describes this reaction?

Iron oxide reacts with aluminum to give aluminum oxide and iron. What kind of chemical reaction is this?

What kind of chemical reaction does the chemical equation sodium + chlorine → sodium chloride represent?

In certain fireworks, potassium nitrate breaks down into potassium oxide, nitrogen, and oxygen. This is an example of a ___________________ (combustion,

decomposition, replacement, synthesis) reaction.

Water breaks down into hydrogen and oxygen.

Leaves make starch using chlorophyll and carbon dioxide.

Food burns in oxygen gas and releases a lot of energy.

Adding vinegar (acid) to baking soda (alkali) give sa product that is neither acidic nor alkaline.