Chemistry Unit 2

by: Nahom Mattyas

What is Matter?

anything that has mas and occupies space.

What is an atom?

The smallest part of an element that has the properties of the element.

What are 6 elements necessary for life?

The six major elements necessary for life are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. These 6 are needed for creating biological molecules.

What is a Cell?

The most basic unit of life.

Atoms are made of protons and neutrons located in the ______, and electrons located in the ______.

nucleus and electron cloud.

Where is most of the atoms mass located?

In the nucleus.

Where is most of the atoms volume located?

Most of the atoms volume is located in the electron cloud.

From the Periodic Table, you can gather an element’s____, the number of positive ____, the identity of an atom, and the number of negative ___

Symbol, protons, and electrons

What is an isotope?

Two or more forms of the same element that have different amounts of neutrons.

The average Atomic mass= the ___ of the protons and neutron in the most common ____ of the element.

sum and isotope.

The electron cloud of an atom is divided into ____ levels, or shells. The inner most level holds up to__ e and most of the other hold up to __e

energy, 2, and 8.

Electrons in the outermost energy level is called ____ electrond

Valence

A ___ on the Periodic Table is a vertical column with similar physical and chemical properties because they have the same ____ electrons.

Group and Valence