States of Matter
Which state of matter has the fastest moving particles? Solid, Liquid, or Gas?
Gas
All atoms of the same element must have the same number of:
a. protons
b. neutrons
c. electrons
a. protons
Protons, neutron, electron.
Proton = +1
Neutron = 0
Electron = -1
Ionic compounds typically have (high or low) boiling and melting points?
High
In which type of reaction is thermal energy transferred from the system to the surroundings?
Exothermic reaction
Melting = solid to liquid
Condensation = gas to liquid
What is a substance made of atoms that all contain the same number of protons and cannot be split into anything simpler by chemical means?
Element
Which subatomic particle has the smallest relative mass?
Electron
Ionic compounds are _______ at room temperature. Which state of matter?
Solid
What is the difference between the system and the surroundings?
System: the reacting chemicals
Surroundings: anything other than the chemicals reacting
Match the following to solid, liquid, or gas:
a. fixed volume and shape
b. no fixed volume; takes shape of container
c. fixed volume; takes shape of container
Solid = a
Liquid = c
Gas = b
What is the difference between a compound and a mixture?
Compounds are chemically combined. Mixtures are not chemically combined.
What is the atomic number?
The number of protons
What is the difference between an ionic and covalent bond?
Ionic bond = transfer of electron
Covalent bond = share electrons
Why does the temperature of the surroundings decrease in an endothermic reaction?
The temperature of the surroundings decreases because thermal energy is taken in / absorbed
Random
Is lemonade a compound or mixture? Why?
What is the mass number?
The number of protons and neutrons
What is the difference between a cation and an anion?
A cation has lost electrons. An anion has gained electrons.
Are cold packs an example of an endothermic or exothermic reaction?
Cold packs for sports injuries are based on endothermic reactions, designed to take heat away from a recently injured area to prevent swelling
What is sublimation?
Phase change from solid directly to gas
Physical
Which element is represented with the electron configuration of 2, 8, 1.
Sodium, Na
What holds positive and negative ions together in an ionic bond?
Strong electrostatic forces of attraction between opposite charges
Where does the energy within the system come from?
The energy within the system comes from the chemical bonds themselves which could be considered as tiny stores of chemical energy