Chapter 6: Atoms, Molecules, Ions Flashcards
What are models?
Models are replicas of “real” objects or events. A model is a simplification and does not represent all aspects of the phenomena or object from which it is derived.
What are some generalisations of a model?
- A model is a representation of an object, event or idea.
- Models help us to understand the actual object, event or idea better.
- Models can be physical, conceptual or mathematical.
- Models have limitations and involve simplifying assumptions.
- Models possess generalizability and sometimes predictive power.
How is models applied in the particulate model of nature?
The particulate model of matter teaches us that all matter is made up of particles in constant, random motion. In this model, we often represent a particle by simplifying it into a circle. This is a limitation of this model as the type of particles would vary depending on which substance we are describing.
What is an atom?
An atom is the smallest unit of an element that retains the chemical properties of that element.
Atoms are typically represented using circles as shown below. (But can’t show in this flashcard)
Colour/shading help us to differentiate between atoms of different elements.
What is a molecule?
A molecule is a group of two or more atoms chemically bonded together, through covalent bonds.
Molecules are typically represented by a cluster of atoms that are touching each other.
The number of each type of atom will depend on the type of substance it represents.
What is an ion?
An ion is an atom or molecule with an electric charge. The electric charge can be either positive or negative.
ions are typically represented as a circle with the charge indicated inside the circle.
Atoms are made up of ____ particles: ___, ___ and _____
Atoms are made up of subatomic particles: protons, neutrons and electrons
Protons and neutrons are packed densely in the ___ of an atom, known as the _____.
Collectively, protons and neutrons are known as ___. Electrons ___around the nucleus.
Protons and neutrons are packed densely in the centre of an atom, known as the nucleus. Collectively, protons and neutrons are known as nucleons. Electrons spin around the nucleus.
What is the relative mass (in atomic mass unit) for proton, electron and neutron?
Proton— 1
Electron—0*
Neutron—1
An electron’s mass is approximately 1/1836 that of a proton, hence it is often regarded as 0 or negligible.
What is the relative charge of proton, electron and neutron?
Proton— +1
Electron— -1
Neutron— 0
What is the definition of mass number?
The mass number (or nucleon number) of an element is defined as the sum of the number of protons and neutrons in its atom.
