Atomic Structures. Flashcards
What is an atom?
The smallest part of an element that can take part in a chemical change.
Each atom is made up of subatomic particles. Name them.
Each atom is made of subatomic particles called protons, neutrons and electrons.
What are protons?
A proton is a positively charged particle found in the nucleus of an atom.
What is a neutron?
A neutron is a subatomic particle with no charge and is found in the nucleus of an atom.
What is an electron?
An electron is a negatively charged particle found orbiting in the shell around a nucleus.
What can collectively be called nucleons?
Protons and neutrons can collectively be called nucleons.
Why is it correct to say that an atom is an electrically neutral entity?
An atom is an electrically neutral entity because they contain equal quantities of positively charged protons and negatively charged electrons.
State the relative charge and approximate relative mass for a proton.
Relative charge of a proton = +1.
Approximate relative mass of a proton = 1.
State the relativle charge and approximate relative mass for a neutron.
Relative charge of a neutron = 0 (neutral).
Approximate relative mass of a neutron = 1.
State the relative charge and approximate relative mass for an electron.
Relative charge of an electron = -1.
Approximate relative mass of an electron = 1/1840.
Define proton number (atomic number).
The proton number (or atomic number) is the number of protons in the nucleus of an atom.
Define nucleon number (mass number).
Nucleon number (or mass number) is the total number of protons and neutrons in the nucleus of an atom.
What is an element?
A substance containing only one type of atom and cannot be split into anything simpler.
For example sodium, chlorine, and argon.
How are elements in the same periodic group similar?
Elements in the same periodic group have the same amount of electrons in their
outer shell, which gives them similar chemical properties.
How are elements arranged in Periods?
Elements are arranged in order of increasing atomic number (proton number), in rows called
periods.
Fill in the missing spaces :
The number of _____ or _____ _____ is the same as the period number.
Elements in the same Group have the same ______ of outer shell ________.
The number of shells or energy levels is the same as the period number.
Elements in the same Group have the same number of outer shell electrons.
What is a compound?
A substance containing two or more types of atoms chemically combined.
For example sulfur dioxide, sulfuric acid, and magnesium oxide.
NOTE - The formation of a compound is irreversible.
What is a mixture?
Two or more substances mixed together but not chemically combined.
Define Isotopes.
Isotopes are atoms of the same element that contain the same number of protons and electrons but a different number of neutrons.
What are the two types of isotopes?
Isotopes can be divided into two types: radioactive and non-radioactive.
Give 1 MEDICAL uses of radioisotopes.
Medical :
- Medical instruments and materials are routinely sterilized by exposure to radiation.
- Radiation is extremely harmful and kills cells, radioisotopes are used to treat cancer.
Give 1 INDUSTRIAL use of radioisotopes.
Industrial:
Radioactive tracers called a Geiger counter is deployed to detect leaks in gas or oil pipes.
Why do isotopes have the same properties?
Isotopes have the same chemical properties because they have the same number of electrons in their outer shell and the number of electrons in the outer shell is responsible for chemical reactions and they also have the same number of protons so are still classed as the same element.
Radioisotopes or radioactive isotopes are unstable, why?
Radioactive isotopes (radioisotopes) are unstable due to the imbalance of neutrons and protons, which causes the nucleus to decay over time.
