Chapter 4 Atoms And Element Flashcards
Define atom
A subatomic or submicroscopic particle that is the building block of matter
Define element
 A substance made up of only one type of atom
What is the atomic theory?
Each element is composed of indestructible particles called atoms. All atoms of a given element have the same mass and properties. Atoms combined in simple whole number ratios to form compounds.
Who was the first to propose the idea of an atom? And what did they believe?
JJ Thompson  and he believed that electrons were uniformly, distributed and present within the atom and in all elements
What was his plum pudding model
It was a description of an atom in which electrons are held in a loose sphere of positive charge or protons
Who tested JJ Thompson’s plum putting model
Ernest Rutherford with his Rutherford gold foil experiment
How did Ernest Rutherford test it?
So alpha particles were shot at atomic thin piece of gold, and were expected to pass through the loose fear of positive charge however, not all of the alpha particles pass through, and some are projected because of this Rutherford concluded that the atom must be made mostly of empty space with a dense positive center
What is the nuclear model of an atom?
Most of the atoms mass is positively charged and at the core known as the nucleus. Most of atoms volume is empty space in which electrons are dispersed. The atom is electrically, neutral, unless ions, which means the electrons equals the protons.
What was later added to the nuclear model of an atom
That’s a nucleus has positively charged in neutral charge, so protons and neutrons
What particles is the atom made up of mostly
The nucleus has majority protons and neutrons electrons contribute to the entirety of the atom not so much
Natural fundamentals of charge
Protons and electrons attract same charges, repel positive and negative charges will cancel each other out if they have the same magnitude
What are elements define by?
Their atomic number for the amount of protons in the nucleus they are also defined by their neutrons, but the neutrons vary
Who noticed the elements have similar
In 1865 Dmitri Mendeleev
What is the period Law?
What elements are arranged in increasing mass and increasing atomic number their properties occur periodically. Also elements in the same group or columns, behaves similarly
Where are metals and what other characteristics
Metals on the left side and the great conductors of heat and electricity, the malleable and ductile, and reactions they lose electrons
Where are nonmetals and what are their characteristics?
Nonmetals on the upper right corner of the periodic table and a zigzag they gain energy and very in physical state
What are metalloids and what are their characteristics?
On the right side in zigzag in between the metals and nonmetals, they have very physical state and are semiconductors
Define transitional element, or metal
Cannot predict amount of electrons lost in a chemical reaction
Define a period and group in the periodic table
 a period is a row wall a group is a column in which elements behave similarly
Do noble gases, chemically react
 No
Are alkaline metals, very reactive and lose electrons
Yes
Define an ion
An atom or molecule that loses or gains electrons
How to find ionic charge
The number of protons minus the number of electrons
Define cation and anion
 Cation are positively charged ions that lose electrons, well and ions are negatively charged ions that gain electrons
