PARTICLE THEORY & MATTER
What state of matter has the least amount of particle movement?
Solid
Is melting ice a physical or chemical change?
Physical change. No new substance is formed, it's still water!
How many protons are in carbon?
6
In a neutral atom protons always equal ________.
What is the name of the chemical family that contains elements that are all stable and unreactive?
Noble Gases
What happens to the spaces between particles when a cube of ice melts?
Particles spread farther apart.
Is dissolving salt in water a physical or a chemical change?
Physical. No new substance is formed, it's still water and salt!
How do you find the number of neutrons in an element?
Subtract the atomic number from the atomic mass.
What is the maximum number of electrons that can go in the first shell of a Bohr-Rutherford Diagram?
2
What two elements make up table salt, NaCl?
Sodium and chlorine.
The particles in a gas can move quickly and are far apart, and will spread out to fill whatever space they are in.
Give one clue that a chemical change has occured.
Gas produced, colour change, heat/light, precipitate.
Which element has the symbol Au?
Gold
How many shells (orbits) would Carbon have? Hint: Carbon's atomic number is 5
2
How many total atoms are in Ca(OH)₂ ?
5
Why does stirring a solution affect the rate at which a solute dissolves in a solvent?
Faster particle movement increases dissolving rate as particles of the solute move quickly to fill spaces between the solvent particles.
Give 3 physical properties of metals.
Physical properties: good conductors of heat/electricity, malleable (can be bent or shaped), dense, etc
Every element has a unique number of this type of particle?
Lithium has an atomic number of 3. How many valence electrons does lithium have?
1
How many oxygen atoms are in Mg₃(PO₄)₂ ?
8
Why does a cold can of soda “sweat” when placed in a warm room?
Warm air particles slow down when they touch the cold can, causing water vapour to condense into liquid droplets.
Why is flammability considered a chemical property?
It involves forming new substances (water vapour, soot, carbon dioxide) during burning.
What is the name for atoms of the same element with the same number of protons but a different numbers of neutrons.
Isotopes
A mystery element has three shells. It has 3 electrons in its last shell. What element is it?
Aluminum (Al)
Explain why hydrogen is more reactive than helium.
Hydrogen does not have a full outer shell of electrons (needs to gain 1 more electron), while helium does.