This type of property can be observed without changing the substance, such as its color or melting point.
Physical property.
This is the simplest form of matter, made up of only one type of atom.
Element.
Elements in the same group have this in common, which explains why they behave similarly in reactions.
The same number of valence electrons.
This type of bond forms when atoms share electrons.
Covalent bond.
Aluminum is used in soda cans because it is lightweight and resists this.
Corrosion.
This type of property involves how a substance reacts, like iron forming rust when exposed to oxygen.
Chemical property.
Two or more elements chemically bonded together form this type of substance.
Compound.
As you move down a group on the periodic table, atoms get larger because this increases.
The number of energy levels.
This type of bond forms when electrons are transferred between atoms, creating charged ions.
Ionic bond.
Titanium dioxide is used in sunscreen because it does this to harmful UV rays.
Reflects them.
When wood burns and turns into ash and smoke, this type of change has occurred.
Chemical change.
If a mixture has visibly different parts, like sand and iron filings, it’s called this.
Heterogeneous mixture.
The most reactive metals are found in this group, which includes lithium, sodium, and potassium.
Group 1 (alkali metals).
Metals form this type of bond where electrons are delocalized and free to move.
Metallic bond.
Copper is commonly used in electrical wiring because it is an excellent conductor of this.
Electricity.
Properties like mass and volume that depend on the amount of material present are known as these.
Extensive properties.
If a mixture looks uniform throughout, like salt dissolved in water, it’s called this.
Homogeneous mixture.
Noble gases, like helium and neon, are unreactive because their outer electron shells are this.
Full.
The oxygen molecule (O2) is held together by this type of bond.
Covalent bond.
Ceramics are used in high-temperature cookware because they are stable under these conditions.
High temperatures
Properties like density and boiling point that do not depend on the amount of material are known as these.
Intensive properties.
In this type of mixture, the individual components retain their properties but are not chemically bonded.
Mixture.
Moving across a period, this property, which measures how strongly an atom attracts electrons, increases
Electronegativity.
Ionic compounds, like salt, have high melting points because of these strong forces between ions.
Electrostatic forces.
Helium is used in balloons instead of hydrogen because it is this.
Non-flammable.
When you see bubbling and fizzing during a reaction, it’s evidence that this type of change has occurred.
Chemical change.
Air, which is evenly mixed, is an example of this type of matter.
Homogeneous mixture.
This group, containing fluorine and chlorine, is the most reactive group of nonmetals.
Group 17 (halogens).
Atoms form chemical bonds because they want to achieve this stable electron configuration.
A full outer shell.
Quartz is used in making glass because it is _____ and transparent.
Hard
This term describes changes like melting, freezing, or boiling, where the substance’s identity stays the same.
Physical change.
Table salt (NaCl) is an example of this type of matter because it contains chemically bonded elements.
Compound.
As you move down a group, it becomes easier to remove an electron because this property decreases.
Ionization energy.
This bond, found in water molecules, forms between hydrogen and highly electronegative atoms like oxygen.
Hydrogen bond.
Stainless steel resists rust and is commonly used in these kitchen tools.
Utensils.
When magnesium reacts with acid, producing gas, this type of property is demonstrated.
Chemical property.
This happens to the properties of substances in a mixture: they remain unchanged.
They retain their original properties.
Elements in the same group form similar compounds because they have the same number of these.
Valence electrons.
Triple bonds, like those in nitrogen gas (N2), involve this many shared pairs of electrons.
Three.
Graphite, used as a lubricant, works because its layers do this easily.
Slide over each other.
This type of change occurs when water freezes into ice but remains chemically .
Physical change.
A molecule is made of two or more atoms, but this type of substance specifically contains two or more different elements bonded together.
Compound.
Elements in this group, like helium and argon, have the highest ionization energies.
Group 18 (noble gases).
Covalent bonds usually form between these types of elements.
Nonmetals.
Sodium is stored in oil to prevent it from reacting violently with this.
Water.
Combustion, where a substance reacts with oxygen to produce heat and light, is an example of this type of change.
Chemical change.
Water (H2O) is a compound because its elements are combined in this specific way.
In a fixed ratio.
As you move down a group, atoms have more energy levels, causing this property to increase.
Atomic radius.
This term describes the outermost electrons involved in bonding.
Valence electrons.
Gold is valuable in electronics because it is highly conductive and resistant to this.
Corrosion.