Chemistry Flashcards
What does the law of definite composition state?
A chemical compound contains the same proportions by mass of the elements regardless of the sample size.
What are the components of an atom?
Protons (p+), Neutrons (n), Electrons (e-)
Where are protons located in an atom?
In the nucleus.
Where are neutrons located in an atom?
In the nucleus.
Where are electrons located in an atom?
In the electron cloud surrounding the nucleus.
What is the kinetic molecular theory?
A theory that explains the behavior of gases based on the motion of particles.
What is the difference between ionic and molecular compounds?
Ionic compounds consist of ions held together by electrostatic forces, while molecular compounds consist of molecules formed by covalent bonds.
What are chemical formulas used for?
To represent the composition of a compound.
What are the physical properties of ionic or molecular compounds?
Properties such as melting point, boiling point, solubility, and electrical conductivity.
What is the significance of groups and families in the periodic table?
Elements in the same group or family have similar chemical properties.
Define pure substances.
Materials made of only one type of particle.
Define mixtures.
Materials made of two or more different types of particles.
What is the difference between mass number and atomic number?
Mass number is the total number of protons and neutrons, while atomic number is the number of protons.
What are physical changes?
Changes that do not alter the chemical composition of a substance.
What are chemical changes?
Changes that result in the formation of new chemical substances.
What is the process of naming ionic and molecular compounds called?
Nomenclature.
What is the difference between heterogeneous and homogeneous mixtures?
Heterogeneous mixtures have visibly different substances, while homogeneous mixtures have a uniform composition.
What are molecular models used for?
To represent the three-dimensional structure of molecules.
What is the difference between chemical and physical properties?
Chemical properties describe a substance’s ability to undergo chemical changes, while physical properties can be observed without changing the substance.
What are qualitative physical properties?
Properties that can be observed without measurement, such as color and smell.
What are quantitative physical properties?
Properties that can be measured, such as mass and volume.
List the three states of matter.
- Solids
- Liquids
- Gases
What are exothermic reactions?
Reactions that release heat.
What are endothermic reactions?
Reactions that absorb heat.
