A measurement must include both a number and a(n) __________.

What is an organized plan for gathering, organizing, and communicating information called?

What are the two main areas of physical science?

What is the variable that changes in response to the manipulated variable called?

What is a statement that summarizes a pattern found in nature called?

What explains a pattern found in nature?

What must always be read and understood before doing lab activities because they can involve hazardous materials?

In scientific notation, what is the result of $$(8.2 x 10^4 m) x (3.7 x 10^2 m)$$ ?

In an experiment, 0.014 seconds equals how many milliseconds?

What is the closeness of a measurement to the actual value being measured called?

In an experiment, if doubling the manipulated variable results in a doubling of the responding variable, what is the relationship between the variables?

Matter that always has exactly the same composition is classified as what?

Pure substances are either __________ or __________.

An element has a fixed composition because it contains only one type of what?

A compound can be made from two or more elements or other __________ joined together in a fixed composition.

The substances in what type of mixture are evenly distributed throughout the mixture?

In what type of mixture are the parts noticeably different from one another?

If the particles in a mixture scatter light, the mixture is either a __________ or a __________.

Measuring what can be used to test the purity of some substances?

If a spoon gets hot quickly when it is used to stir a pot of soup, it is probably made of what?

A material used for electrical wiring would need to have good what?

What is a process that could be used to separate dissolved particles from the liquid in a solution?

A(An) ____________________ change occurs when a material changes shape or size but the composition of the material does not change.

____________________ properties can be observed only when the substances in a sample of matter are changing into different substances.

Rust forms because iron and oxygen are highly ____________________ elements.

A solid that forms and separates from a liquid mixture is a(an) ____________________.

A cake rises as it bakes because a chemical change causes ____________________ to be produced.

Unlike Democritus, Aristotle did not believe that matter was composed of tiny, indivisible ____________________.

John Dalton concluded that all the atoms of a single ____________________ have the same mass.

John Dalton observed that elements always combine in the same ratio to form a particular ____________________.

The subatomic particle that J.J. Thomson discovered has a(an) ____________________ charge.

In Rutherford’s gold foil experiment, alpha particles that bounce straight back from the foil have struck ____________________ in the gold atoms.

In Rutherford’s gold foil experiment, some of the ____________________ aimed at gold atoms bounced back, suggesting that a solid mass was at the center of the atom.

The results of Rutherford’s gold foil experiment demonstrated that the ____________________ occupies a very small amount of the total space inside an atom.

Protons and ____________________ are found in the nucleus of an atom.

Neutrons and ____________________ have almost the same mass.

If element Q has 11 protons, its atomic ____________________ is 11.

The nuclei of isotopes contain different numbers of ____________________.

The __________________________ of an isotope is the sum of the number of protons and neutrons in its nucleus.

The difference between a sample of heavy water and regular water is that a hydrogen atom in heavy water has an extra __________________________.

In Bohr’s model of the atom, __________________________ move in fixed orbits around the nucleus.

When an atom gains or loses energy, some of its __________________________ may move between energy levels.

The moving blades of an airplane propeller provide an analogy for the electron __________________________ model.

The region in which an electron is most likely to be found is called a(an) __________________________.

When all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its __________________________ state.

An atom in which an electron has moved to a higher energy level is in a(an) __________________________ state.

When Mendeleev organized elements in his periodic table in order of increasing mass, elements with similar properties were in the same __________________________.

Mendeleev organized elements in his periodic table in order of increasing __________________________.

Mendeleev’s periodic table was useful because it enabled scientists to predict properties of unknown __________________________.

The pattern of repeating properties of elements revealed in the periodic table is known as the __________________________.

Phosphorus is one block to the left of sulfur in the periodic table. The atomic number of sulfur is 16. What is the atomic number of phosphorus?

The atomic mass unit (amu) is defined as one-twelfth the mass of a(an) __________________________-12 atom.

To determine the atomic mass of an element, you would take a(an) __________________________ average of the isotopes that make up that element.

Elements can be classified as metals, nonmetals, and __________________________.

Metals that grow dull when exposed to air are more __________________________ than metals that remain shiny.

The elements potassium (K), calcium (Ca), and scandium (Sc) appear from left to right in Period 4 of the periodic table. Among these elements, the most reactive is __________________________.

From left to right across a period in the periodic table, elements become less __________________________ and more __________________________ in their properties.

Element 3, lithium, has one valence electron, and element 4, beryllium, has two valence electrons. Element 5, boron, has __________________________ valence electrons.

Hydrogen does not have the typical properties of a metal. However, hydrogen is located above Group 1A because it has one __________________________.

In general, a(an) ____________________ metal will be more reactive than an alkaline earth metal in the same period.

The two most reactive groups of elements in the periodic table are the alkali metals and the ____________________.

Although they are called ____________________ lights, they can contain any noble gas.

Reactive elements, such as alkali metals and halogens, are found in nature only as ____________________.

Fertilizers usually contain two elements from Group 5A, which are ____________________ and phosphorus.

One way to demonstrate reactivity among the alkaline earth metals, Group 2A, is to observe what happens when they are placed in ____________________.

In an electron dot diagram, each dot represents a(an) ____________________.

In an ionic compound, the attractions between cations and ____________________ hold the compound together.

The chemical formula for calcium chloride, CaCl₂, shows that the compound contains two ____________________ ions for every ____________________ ion.

KBr is the formula for an ionic compound. The fact that neither symbol is followed by a subscript means that there is a(an) ____________________ ratio of ions in the compound.

The ions in solid sodium chloride are arranged in a structure called a(an) ____________________ lattice.

If there are two long dashes between two atoms in a structural formula, molecules of the compound contain a(an) ____________________ bond.

A polar covalent bond forms when ____________________ are not shared equally between atoms.

Two factors that determine whether a molecule is polar are the types of atoms in the molecule and the ____________________ of the molecule.

When cesium and fluorine react, they form an ionic compound called cesium ____________________.

A(an) ____________________ ion is a covalently bonded group of atoms that has a positive or negative charge.

In ionic compounds, the sum of the charges of all the cations and anions must be ____________________.

The compound whose formula is SO₃ is called sulfur ____________________.

The metallic bonds in a transition metal, such as tungsten, are stronger than the metallic bonds in a(an) ____________________ metal, such as sodium.

In general, the more ____________________ a metal has, the stronger its metallic bonds will be.

Among the elements potassium, lithium, and iron, the metallic bonds are likely to be strongest in ____________________.

The statement that in chemical reactions, the total mass of the reactants equals the total mass of the products is the law of ____________________.

In an experiment, 44 g of propane were burned, producing 132 g of carbon dioxide and 72 g of water. The mass of oxygen that was needed for the reaction was ____________________.

A(An) ____________________ is the number that appears before a formula in a chemical equation.

The molar mass of the chlorine diatomic molecule is ____________________.

A sample of HBr contains 186 g of the compound. The sample contains ____________________ moles of HBr.

Butane burns as shown in the balanced chemical equation 2C₄H₁₀ + 13O₂ → 10H₂O + 8CO₂. If 6 mol of butane burn, ____________________ mol of carbon dioxide are produced.

Single-replacement reactions can take place with nonmetals. In the following equation, assume that A and C are nonmetals and B is a metal. Complete the following general equation for the replacement of a nonmetal in a compound by another nonmetal: A + BC → ____________________.

The element ____________________ is always present in a combustion reaction.

In a double-replacement reaction, there are two reactants and ____________________ product(s).

What is the SI unit of mass?

Which term refers to a substance made of only one kind of atom?

What is the term for a variable that responds to changes in an experiment?

Which of the following is a noble gas?

What is the atomic number of nitrogen?

What is the term for a negatively charged particle in an atom?

Which law states that the properties of elements are periodic functions of their atomic numbers?

What is the chemical symbol for carbon?

What is the term for a mixture in which the components are evenly distributed?

Which element has the chemical symbol O?