U1 - Module 3: Analyzing Particles Flashcards
What determines a substances identity, properties, and behavior?
The nature of its particles
What do we assume to explain the different properties of substances?
Substances are made of particles with different compositions and structures.
Chemical Bonds
Strong attractive forces that hold atoms together.
What are pros and cons of the ball and stick model?
Pro: Easy to see the bonds
Con: Not correct size
Why are the interactions different between particles in different substances?
Different particle composition and structure.
Mixtures
Composed of 2+ types of independent particles whose presence vary in proportions in each sample.
What are different substances made of?
Free atoms and bonded atoms
What is the core assumption of modeling substances?
The composition and structure of the particles that make up a substance is the key differentiating characteristic.
What do different types of particles combined lead to?
Different substances
How can different components of a mixture be separated?
Filtration and distillation
Elementary Substances
The simplest substances in nature composed of identical particles made of free/bonded atoms of the same type.
Chemical elements
Elements on the periodic table
What elements are easily atomic in nature?
Noble gases
Chemical compounds
Substances composed of identical particles made of bonded atoms of 2+ different types.
Molecular Compounds
Compounds made of nonmetals.
Space Filling
Model of a compound where the particles are all fused together
Ball and Stick
Model of a compound that displays the bonds between different atoms.
Molecular Formula
The formula of the compound
Ex) CH2O
Structural Formula
Lewis Structure
Ionic Compounds
Compounds made of metals and non-metals
Formula Unit
The proportion of which ions are combined in a chemical formula
What can be a major differentiating characteristic when comparing different compounds?
Particle mass (not always)
At standard conditions, what is the relationship between atoms and different elements?
All elements have the same number of atoms at standard conditions.
How do scientists indirectly measure the masses and sizes of atoms/molecules?
Compare the masses of samples of different substances when they are the same number of particles.
Relative Mass
The mass of the element located on the periodic table
Avogadros Number
6.022 x 10^23
What is avogadros number also known as?
1 mole
Molar Mass is also known as…
Relative mass
How do you convert from grams of a substance to moles?
Divide by the molar mass of the substance
How do you convert from moles to particles?
Multiply by avogadros number
How do you convert from particles to moles?
Divide by avogadros number
How do you convert from moles to grams?
Multiply by the molar mass of the substance.
What is the formula of density?
D = m (g) / V (mL)
Atomic Species
One specific element
What are the pros and cons of the space filling diagram?
Pros:
- Accurate size
- Visualizes surface features
Cons:
- Difficult to see bonds of atoms
- Low detail for smaller molecules (hard to interpret)
What are the pros and cons of the Ball and Stick diagram?
Pros:
- Clear 3D representation
- Easy to see bonds
- Color coordinated atoms
Cons:
- Not correct sizing scale
- Hard to create for complex molecules; cluttered
