The number of protons and neutrons in the nucleus of one atom of the element.

a horizontal row (left to right) in the periodic table

The image shows a model of a substance. How is the substance classified?

A student reads three statements from a science book.

1. 1. The atoms or molecules in a solid state are closely packed and are fixed at their positions.

2. 2. The particles in a liquid state slide past one another and have spaces between them,

3. 3. The particles in a gaseous state move randomly in all directions and are the farthest apart.

The student uses the information to make a particle model representing the molecules of water in the three states: ice, water, and water vapor. Which model is correct?

Examine the portion of the periodic table that contains neon, an unreactive gas in Group 18. Which element would have similar properties to neon, and why?

It describes how likely an element is to form bonds with another element

A teacher asks her students to classify the substances listed in the table shown as elements, compounds, or mixtures.

A student claims that all of the substances are compounds. Which statement correctly describes the student’s claim?

A student heats a beaker of water and constructs a graph based on the recorded observations.

What can be concluded from the portion of the graph where the temperature remains constant?

A student examines a periodic table with two elements (X and Y) labeled. How can X and Y be classified?

a vertical column (up and down) on the periodic table.

The table lists the properties of substance A.

Which term best describes substance A

An engineer attempts to pull two different materials, X and Y, into wires. Material X can easily be drawn into a wire, but material Y quickly breaks into pieces. The engineer concludes that material X is a metal, and material Y is a nonmetal. Which statement correctly supports the conclusion made by the engineer?

A student performs an investigation with water and table salt. The student lists the steps of the investigation and observations in a table. Which table correctly classifies the matter obtained in both steps of the investigation?

Where are nonmetals found on the periodic table?

A student adds 100 mL of water to three similar containers (1, 2, and 3) made of different materials and places the containers outside for two weeks. The student observes that no changes occur in container 1, but rust forms in containers 2 and 3. What can likely be inferred about the nature of the containers?

A student compares the physical properties of two unknown substances, X and Y. The student’s observations are shown in the chart. Based on the student’s observations, which additional property can be included in the chart?

At its boiling point, a liquid becomes a_______.

Mass divided by volume is the formula for calculating----

Which of these is a mixture?

Outermost electron of an atom and participates in chemical bonding.

Group of chemical symbols and numbers that represent elements and numbers of atoms of each element that make up a compound.

Forms when two atoms share one or more pairs of valence electrons.

Why do noble gases NOT form compounds readily?

In general, metals are ___________.

Students can introduce a sample of gas into a chamber with a moveable divider. The divider allows them to change the portion of the chamber occupied by the gas. When the volume of the gas is reduced, what change in property would be the most reasonable to expect?

Which of the samples shown represents an element?

A bond is formed when an electron is transferred from a sodium atom to a chlorine atom. What happens to the sodium atom during this process?

An atom can best be described as

The formation of an ionic bond involves the

In the reaction shown, iron reacts with water to form iron oxide and hydrogen gas. Which of these best describes the iron (Fe) reactant?

Alyssa investigates properties of matter. The answer to which question would best determine whether a substance is an element or a compound?

Ice molecules take up more volume than liquid water molecules. Which of these conditions occurs when water in a pond freezes?

When potassium and bromine atoms form chemical bonds, which of these is produced?

Structural differences between different chemicals can be represented in models of the particles. Which drawing best represents a compound?

the muffins baked for 20 minutes until done

How many atoms are in one formula unit of the compound FeC5O5?

It is made up of two or more compounds.

Its components keep their own properties.

a solution

These statements describe an

The products of a reaction have the same ________as the reactants.

Number IN FRONT of reactants or products

Number BELOW on an element

Which chemical formula accurately represents the provided model?

pink-Na. green-Cl. yellow-S. blue-H

Is the following equation, balanced or unbalanced? 4 Fe + 3 O2 --> 2 Fe2O3

Is the following equation, balanced or unbalanced? SnO2 + 2 H2 --> Sn + 2 H2O

Balance the following equation--> What coefficient would need to be put in front of HCl to balance this equation. CH4 + 4 Cl2 → CCl4 + _____ HCl

How does the concept of conservation of mass apply to chemical reactions?

Which scientific law is best demonstrated by the reaction shown in the diagram?

A student mixes baking soda with acetic acid in a test tube. The student observes the formation of a gas and records the two reactions that occur.

The student concludes that the combination of the two reactions follows the Law of Conservation of Matter. Which statement supports the student’s conclusion?