Chemistry(substance changes, atoms and ions) Flashcards
What is a physical change
Does not change the chemical properties of a substance and no new substance is formed
What is a chemical change
Forms a new substance with new chemical properties
What are the five clues of a chemical change
1.new colour
2.heat or light is produced or absorbed
3.a solid is formed in a liquid
4.gas bubbles are formed
5.the change is very hard to reverse
What are physical properties
Physical attributes of a substance
What are examples of physical properties
Colour, density, texture, solubility, smelly, melting point
What are chemical properties
What a substance does at it changed into a new substance
Examples of chemical properties
Acids will dissolve metals, combustion
Why is a qualitative property
A property that cannot be measured with a numerical response
What is a quantitative property
A property that can be measured with a numerical response
How do you calculate the number of protons, electrons and neutrons in an atom
of Protons= atomic mass
# of electrons= same number as protons
# of neutrons= atomic mass subtract the atomic number
What is the difference between atoms and ions
Atoms
-smallest unit of an element
-you cannot create or destroy them
-all atoms of an element are identical
Ions
-atoms that have become charged by positive or negative electrons
-electrically charged rather than neutral
What are cations
Positively charged ions
What are anions
Negatively charged ions
What is ionic bonding
One atom looses valence electrons and gains them from another atom
What is covalent bonding
The sharing of electron pairs between atoms
