Bonding
How is a covalent bond formed (think electrons)?
Electrons are shared between two atoms
The atomic number of an element represents the number of ______ in an atom?
Protons
What substance can NOT be broken down into simpler substances?
An element
What does exothermic mean?
Heat exits/is released making it feel hotter
What part of an atom contains the positive charges
Nucleus/Protons located in the nucleus
How is an ionic bond formed (think electrons)?
Electrons are transferred from one atom to another
Elements are arranged in the periodic table according to increasing...
Atomic number
Salt (NaCl) can be identified as a ________.
Compound
What does endothermic mean?
heat enters/is absorbed making it feel colder on the outside
What are valence electrons?
Electrons located in the outermost shell of an atom
Why do atoms form bonds?
To become more stable
These types of elements are good conductors of heat
Metals
What kind of mixture appears to be mixed evenly throughout?
A homogenous mixture
What is a chemical reaction?
a new substance/product is made
How many different types of atoms make up a molecule of carbon dioxide (CO2)?
2 different types of atoms (C and O)
Carbon (C) has 6 electrons in it's valence (outer) shell. Which atom is Carbon likely to bond with?
Sulfur (6 valence electrons.)
Bromine (7 valence electrons)
Beryllium (2 valence electrons)
Hydrogen (1valence electron)
Beryllium (2 valence electrons)
Why are noble gasses (Group 18) so unreactive?
Their outer shell is full
Koolaid is made by mixing a powder into water. This is an example of a __________.
Mixture
Identify if this is a chemical or physical change:
A substance has melted
Physical change
When is an atom most stable?
When it has a full outer shell (typically 8 valence electrons)
Which type of elements generally form ionic bonds?
A nonmetal and a metal
How many neutrons does an atom of copper (Cu) contain if the atomic number is 29 and the atomic mass is 63?
34 neutrons
Soda with ice is an example of a ___________ mixture.
A heterogenous mixture
Identify if this reaction is balanced or unbalanced:
CH4 + O2 --> CO2 + H2O
Unbalanced because there are only 2 hydrogens on the right, while there are 4 hydrogens on the left. There are also three oxygens on the right, but only 2 on the left
Identify the reactants and products of the following reaction:
2Mg + O2 --> 2MgO
Reactants: Mg and O2
Products: MgO