U1 Structure of Matter Study Guide

Book J, Chemistry

What is matter?

anything that has mass and takes up space

What is matter made up of?

elements

How are the elements arranged

by atomic number

What is the smallest part of an element?

an atom

What are atoms made up of?

protons, neutrons, and electrons

Why are atoms neutral?

the number of protons are equal to the number of electrons

What does the atomic number of an element represent?

their number of protons (and electrons)

What does the mass number represent?

the number of protons and neutrons combined

Elements join together by attractive forces called chemical bonds to form _____ and _____

molecules and compounds

Are chemical bonds a physical connection?

no

What is a physical property?

something that can be observed or measured without changing the identity of the substance

What is a chemical property?

something that can be observed or measured as a substance changes in identity

Examples of physical properties:

appearance, texture, color, order, melting point, boiling point, density, solubility, viscosity, etc.

Examples of chemical properties:

flammability, reactivity, etc.

Formula for density:

D = M / V

Formula for the volume of a rectangular box:

V = L x W x H

What is ionic bonding?

a type of chemical bond when electrons are transferred between two atoms

What is covalent bonding?

a type of chemical bond when two atoms share electrons

Why do the elements in the same group have similar properties?

they have the same number of valence (outer) electrons

What is an isotope?

Atoms of the same element that have different atomic masses.

What is an ion?

An atom that has either gained or lost electrons.

What is the smallest unit of a compound that keeps all the properties of that compound?

molecule

What is mass?

a measure of the amount of matter in an object measured in grams.

Between what types of atoms does ionic bonding occur?

a metal and a nonmetal

Between what types of atoms does covalent bonding occur?

Between two nonmetals.

What is the density of freshwater?

1 g/cm³

If mass goes up and volume stays the same, density _____

increases

If mass stays the same and volume increases, density _____

decreases

1 ml = __ cm³

1

In order to float in fresh water, the overall density of an object must be ___ than 1g/cm³

less