CHM031 M1 SA W1 Flashcards
What is the study of chemistry primarily focused on?
Study of matter, transformations of matter, and behavior of matter
Chemistry investigates how different substances interact, change, and behave under various conditions.
Define matter.
Occupies space, has mass, consists of atoms and molecules
Matter can be found in various states, including solid, liquid, and gas.
What are the two main scales of chemistry?
Macroscopic and atomic
The macroscopic scale refers to matter visible to the naked eye, while the atomic scale involves individual atoms and molecules.
What is meant by the macroscopic scale in chemistry?
Matter that can be seen with the naked eye
Examples include a piece of copper or a liquid in a beaker.
What does the atomic scale refer to?
Nanoscale or molecular scale
At this scale, individual atoms and molecules cannot be seen.
What is the purpose of chemistry as an experimental science?
To design thoughtful experiments and make careful observations of macroscopic amounts of matter
Chemistry relies heavily on experimentation and observation to understand matter.
What is the scientific method?
Examining results to see if there are alternative ways to interpret the data
This method is crucial for verifying hypotheses and theories in science.
What are qualitative observations?
Observations involving color, appearance, and statements without measurements or numbers
Examples include describing an object as ‘large’ or ‘hot’.
What are quantitative observations?
Quantity or attribute that is measurable, expressed with numbers and units
Dimensions include mass, time, distance, volume, density, temperature, and color.
Give an example of a quantitative observation.
Weighing out 6.25 grams of NaCl or measuring the temperature of an object to be 27 °C
Quantitative observations provide precise and objective data.
Fill in the blank: Scientific observations can be classified as _______ or _______.
Qualitative or quantitative
This classification helps in the systematic study of matter.
True or False: Qualitative observations involve numerical measurements.
False
Qualitative observations are descriptive and do not include numbers.
What is required for careful observations in chemistry?
All ideas are open to challenge
This principle encourages critical thinking and scientific inquiry.
What is chemistry?
Transformation and Behavior of matter
other term for atomic and molecular level?
Microlevel
It is examining results to see if there are alternative ways to interpret data
Scientific Method
What is the simplest type of matter?
Element
Elements are pure substances that cannot be broken down further.
How many elements are recorded on the periodic table?
118
What is an atom?
Smallest indivisible unit of an element
Define a chemical compound.
Substance formed when two or more elements are combined in a defined ratio
What is a molecule?
Collection of atoms held together by chemical bonds
What characterizes pure substances?
Contain only one type of element or compound and have a fixed chemical composition
List some physical properties.
- Physical state
- Color
- Viscosity
- Opacity
- Density
- Conductivity
- Melting and boiling points
What is a mixture?
Substance made up of two or more elements or compounds that have not reacted chemically
What are the two types of mixtures?
- Homogeneous
- Heterogeneous
What defines a homogeneous mixture?
Constant composition throughout the material
What defines a heterogeneous mixture?
No uniform composition
How can mixtures be separated?
By physical means
List methods for separating mixtures.
- Solubility
- Filtration
- Density
- Decantation and centrifugation
- Boiling point
- Distillation
- State of matter
- Chromatography
- Magnetism
What are the three states of matter?
- Solid
- Liquid
- Gas
What is the characteristic of solids?
Have a definite shape and closely packed particles
What is the characteristic of liquids?
Flow and take on the shape of the container
What is the characteristic of gases?
No fixed shape or volume; particles are spaced widely apart
What is a physical change?
Change in the physical property of a substance without altering its chemical composition
What is the melting point?
Temperature at which a solid is converted to a liquid
What is the freezing point?
Temperature at which a liquid is converted to a solid
What is the boiling point?
Temperature at which a liquid is converted to a gas
What are intensive properties?
- Color
- State of matter
- Melting point
- Boiling point
- Density
- Solubility
- Viscosity
- Ductility
- Conductivity
- Malleability
What do chemical properties involve?
Chemical change in a material and substances interacting with other chemicals
Define a chemical change.
Change in the chemical composition of the material
True or False: Methanol is highly flammable because it reacts with oxygen in the air.
True
they are pure substances; cannot be broken down further
Element
substance formed when 2 or more elements are combined in a defined ration
Chemical Compound
collection of atoms held together by chemical bonds
Molecule
contain only one type of element/ compound and fixed chemical composition
Pure Substances
made up of 2 or more elements/compounds that haven’t reacted chemically; not a pure substance
Mixture
constant composition
Homogeneous
no uniform composition
Heterogeneous
substances interacting with other chemicals
Chemical Property
