Chapter 2: The Chemical Properties Of Life Flashcards
What are all organisms composed of?
Matter
What is matter?
Anything that has mass and takes up space
What is an element?
A substance that cannot be broken down any further
What is a compound?
A substance consisting of 2 or more elements.
About how many elements are essential to human life?
25
What 4 elements make up 96% of the human body?
Nitrogen, oxygen, carbon and hydrogen.
What are the trace elements?
Elements that are essential but only in small quantities
How does salt illustrate emergent properties?
A compound sometimes has different traits than an element, the elements that make up salt are, in their pure forms, a poisonous gas and a metal
What is an atom?
The smallest unit of matter that still retains the properties of an element
What is a proton?
A subatomic particle with a positive charge
What is an electron?
A subatomic particle with a negative charge
What is a neutron?
A subatomic particle with a neutral charge
What is a nucleus in terms of an atom?
The center of the atom where protons and neutrons are located
What is an atomic number?
- the number of protons in an atom
- each element has its own specific number
What is a mass number?
-the total protons and neutrons in an element
What is the atomic mass?
The total mass of the protons, neutrons and electrons, but because electrons weigh so little it is approximately equal to the mass number
What is an isotope?
An element with the same number of protons but different number of neutrons than typical. It behaves the same in chemical reactions, however, its properties are different from that of the normal element.
What is a radioactive isotope?
An isotope that’s nucleus decays spontaneously giving off particles and energy
How can radioactive isotopes be beneficial?
They can be used to tag chemicals and make them traceable within the body
How can radioactive isotopes be harmful?
Uncontrolled exposure can lead to damage of the DNA and cancer
How do electrons effect the atom chemically?
Their mass increases as they go away from protons
What are electron shells?
Electrons can only be found in certain parts of the atom, these parts are called electron cells.
What are orbitals?
Electrons can only be found in certain parts of electron shells, these are orbitals. The first electron cell only has one orbital and can only hold two electrons, after that electron shells have four orbitals and can carry 8 total electrons.
How are chemical properties decided?
It is only the number of electrons in the last cell, called the valence shell that contribute to chemical properties.
