Chapter 2 - Atoms and Elements Flashcards
(18 cards)
What are the 2 most abundant elements?
Oxygen (O) and Silicon (Si)
What are the human body’s four most abundant elements?
Hydrogen (H), oxygen (O), carbon (C), and nitrogen (N)
What are the 5 main ideas of Dalton’s Atomic Theory?
*The existence of atoms in matter.
*All atoms of the same element are identical.
*Different elements have different types of atoms.
*Atoms cannot be created, destroyed, or subdivided.
*Chemical compounds are made up of at least two atoms of different elements.
What parts of Dalton’s Atomic Theory were disproved?
- All atoms of the same element are identical. (Isotopes disproves this as they are capable of having different masses (Different # of neutrons) despite being the same element).
- Atoms cannot be created, destroyed, or subdivided. (Atoms can be subdivided into protons, neutrons, and electrons - subatomic particles.)
What is the Law of Constant Composition?
In any particular chemical compound, all samples of that compound will be made up of the same elements in the same proportion or ratio
What is the difference between an element and a compound?
An element is a substance that cannot be broken down into simpler substances. A compound is a substance composed of two or more elements in fixed definite proportions that is capable of breaking down into simpler substances.
What was Thomson’s Plum Pudding Model?
A model proposed by English Physicist J.J Thompson that the negatively charged electrons were small particles held within a positively charged sphere. This model has been disproven by Ernest Rutherford.
What are the features of a proton?
- Charge: Positive
- Atomic Mass: 1.0073 amu
- Location in Atom: The Nucleus
What are the features of a neutron?
- Charge: Neutral
- Atomic Mass: 1.0087 amu
- Location in Atom: The Nucleus
What are the features of a electron?
- Charge: Negative
- Atomic Mass: 0.00055 amu
- Location in Atom: The Orbital
What are isotopes?
Atoms with the same number of protons but different numbers of neutrons. They share almost the same chemical properties, but differ in mass and physical properties.
What are in the atomic symbol
The atomic # of the element on the top, the mass of the element on the bottom.
What are ions?
An atom or group of atoms that has an electric charge. An cation has a positive charge and an anion has a negative charge.
What is a physical change?
The appearance or form of the matter changes but the kind of matter in the substance does not.
What is a chemical change?
The kind of matter changes and at least one new substance with new properties is formed.
What is Ionization?
Energy required to remove an electron?
What is Electron Affinity?
Energy released when e– is added to a natural element.
What are valence electrons?
The outermost electrons in an atom.
