A: Chemistry = Chemical Changes 1.2 Atomic Bonding and Properties Flashcards
What is the stability condition for an atom?
An atom is most stable when its outer energy level is full of electrons.
This principle is fundamental in understanding atomic bonding.
How can atoms achieve full outer energy levels?
Atoms can obtain full outer energy levels by:
* Gaining electrons
* Losing electrons
* Sharing electrons with other atoms
This process is critical in forming chemical bonds.
What charge does an atom acquire if it gains electrons?
Negatively charged.
Gaining electrons increases the negative charge due to the excess of negatively charged particles.
What charge does an atom acquire if it loses electrons?
Positively charged.
Losing electrons results in a deficiency of negatively charged particles, leading to a positive charge.
What is the relationship between negatively and positively charged particles?
Negatively charged particles and positively charged particles attract each other.
This attraction is fundamental in the formation of ionic bonds.
What happens when similarly charged particles interact?
Similarly charged particles repel each other.
This repulsion is a key concept in understanding atomic interactions.
What is the first step in sketching the atomic structure of substances?
Identify the atomic structure of the substance.
This is the foundational step before drawing the diagrams.
What is aluminium classified as?
A metal
Aluminium possesses lustre, good heat and electrical conductivity, malleability, and ductility.
What are the characteristics of metals?
Malleable, ductile, lustrous, good heat and electrical conductivity
Metals can be hammered into shapes and stretched into wires.
What is the definition of a metal?
A malleable and ductile element that has lustre, has good heat and electrical conductivity, and tends to form positive ions
Metals are found to the left of the staircase line on the periodic table.
What is the definition of a non-metal?
An element that is not flexible, does not conduct electricity, and tends to form negative ions
Non-metals are located to the right of the staircase line on the periodic table.
Fill in the blank: A _______ is an element that is not flexible and does not conduct electricity.
non-metal
Non-metals typically form negative ions.
Fill in the blank: A _______ is a malleable and ductile element that conducts heat and electricity.
metal
Metals like aluminium have distinct properties that differentiate them from non-metals.
True or False: Non-metals are generally good conductors of electricity.
False
Non-metals do not conduct electricity.
What type of ions do metals tend to form?
Positively charged ions or cations
What type of ions do non-metals tend to form?
Negatively charged ions or anions
When handling a piece of aluminum, what type of ions are you holding?
A collection of positive ions
True or False: Aluminum ions are negatively charged.
False
Fill in the blank: Metals form _______ while non-metals form _______.
cations; anions
What is rock salt primarily composed of?
Sodium chloride
Rock salt is a compound formed from sodium and chlorine.
What type of compound is sodium chloride?
Ionic compound
An ionic compound is formed from a metal and a non-metal.
What are the two elements that make up sodium chloride?
- Sodium
- Chlorine
What type of bond holds the ions in sodium chloride together?
Ionic bond
An ionic bond is formed by the attraction between positive and negative ions.
What is the force of attraction between positive sodium ions and negative chloride ions called?
Ionic bond
What is a compound?
A pure substance formed from atoms of two or more elements with different atoms joined in fixed ratios
What is an ionic compound?
A pure substance formed from a metal and a non-metal
True or False: Sodium chloride forms rectangular crystals.
True
The structure of sodium chloride contributes to its crystalline shape.
Fill in the blank: An ionic bond is formed by the _______ attraction between positive and negative ions.
simultaneous
What are plastics primarily made up of?
Carbon and hydrogen atoms
Plastics are considered molecular compounds due to the non-metal nature of carbon and hydrogen.
What is a molecular compound?
A pure substance formed from non-metals
Molecular compounds consist of atoms held together by covalent bonds.
What type of bond is formed by the simultaneous attraction of two nuclei for a shared pair of electrons?
Covalent bond
Covalent bonds occur in molecular compounds where non-metal atoms share electrons.
What is a molecule?
A particle containing a fixed number of covalently bonded, non-metal atoms
Molecules are the result of covalent bonding between non-metal atoms.
True or False: Molecular compounds involve ions.
False
Molecular compounds are characterized by the absence of ionic bonds.
Fill in the blank: The combination of carbon and hydrogen atoms is called a _______.
Molecule
Molecules are formed when non-metal atoms bond covalently.
What is the relationship between the nucleus of a carbon atom and the nucleus of a hydrogen atom in a covalent bond?
Both nuclei are simultaneously attracted to the same electrons
This attraction results in the formation of a covalent bond.
What is polycarbonate?
A type of plastic used to make CDs, consisting of long molecules built around a backbone of over a thousand carbon atoms.
What are potential future applications of polycarbonate?
A plastic coating for automobiles that is scratchproof.
Automotive: PC has several applications, including headlight lenses, interior components, and sunroofs, thanks to its impact resistance and lightweight properties
Polycarbonate is transparent, impact-resistant, and is often used to make headlight covers as well as car bumpers.
Polypropylene is used the most frequently of any plastic in automotive manufacturing. Being a thermoplastic polymer, it can easily be formed into almost any shape. It has excellent chemical and heat resistance and is generally resistant to impact.
Why is recycling plastics like polycarbonates important?
Due to their strength, durability, and resistance to environmental effects, which complicates disposal and increases landfill space concerns.
What makes recycling polycarbonates from CDs difficult?
The thin metal coating on CDs.
What has been developed to reclaim polycarbonate from CDs?
Special recycling centres for the manufacture of automobile parts.
Fill in the blank: Polycarbonates are used to make a variety of _______.
[consumer goods]
What are the properties of polycarbonate that make it desirable?
- Strong
- Durable
- Resistant to heat
- Resistant to cold
- Resistant to water
- Resistant to weather
- Resistant to ultraviolet light
True or False: The recipe for polycarbonate cannot be varied.
False
What is a significant liability of plastics like polycarbonates?
Their difficulty in disposal due to their durability.
What is responsible for metals being good conductors of heat?
Free electrons
Free electrons allow for quick energy transfer in metals.
How do positive ions in metal react when exposed to heat?
They begin to vibrate more
This increased vibration is a response to the heat applied.
What happens to energy when a piece of metal is heated?
Most of the energy is transferred to nearby free electrons
This energy transfer is more efficient than in ionic crystals or molecular compounds.
How do free electrons transfer energy in a heated metal?
They move to the cold end of the metal and transfer energy to another positive metal ion
This causes the adjacent ion to vibrate more.
What is the heat transfer process like in ionic crystals or molecular compounds?
Heat is passed from one vibrating ion or atom to its neighbor, which is a much slower process
This lack of free electrons results in less efficient heat transfer.
