Noggin Knockers. The Atom. Periodic Table. Chemical Formulas. Chemical Reactions. Real World. Bonding. 100. 100. 100. 100. 100. 200. 200. 200. 200. 300. 300. 300. 300. 300. 400. 400. 400. 400. 400. 500. 500. 500. Final Jeopardy. The Atom for 100.
A substance that cannot be broken down into any other substance is called a(n) _______________. The smallest particle of this substance is called a(n) ____________.
Smallest particle = atom
What is the greatest number of VALENCE electrons an atom can have?
8 valence electrons
What’s the difference between a compound and a mixture?
Compound- 2 or more different atoms bonded together.
Mixture- several different substances in a container that are NOT bonded together.
Where are the protons, neutrons, and electrons located within an atom?
Protons and neutrons are in the nucleus.
Electrons are in a cloudlike region outside of the nucleus.
Compare and contrast protons, neutrons, and electrons in terms of their charge.
proton: +1 charge
neutron: 0 charge
electrons: -1 charge
Each family or group in the periodic table contains elements with similar properties due to the number of _______________.
When atoms of elements from Group 2 form ions, they tend to have what charge and WHY?
+2 charge because they tend to lose 2 valence electrons so they have a filled outer electron shell (with 8 valence electrons)
If atoms of group 6A (or 16) gain 2 electrons, then how many valence electrons do they have and what charge do they have?
8 valence electrons with a –2 charge.
Determine the number of protons and neutrons of the most common isotope of lithium (atomic number = 3, average atomic mass = 6.9 amu).
3 protons and 4 neutrons
The atomic masses listed on the periodic table are usually not whole numbers. For example potassium’s atomic mass is 39.100 amu. Explain why this is the case.
The atomic masses on the periodic table are the average masses of the naturally occurring isotopes of that element.
The atomic particles involved in the bonding between atoms are the ____________.
What is a single bond?
1 pair of electrons shared between 2 atoms.
Identify the following compounds as an ionic or molecular compound based upon the information given: sodium chloride (NaCl)- melting point is about 800oC, conducts electricity in water; water- boils at 100oC.
Sodium chloride is an ionic compound- it contains a (+) and (-) ion plus it has a high melting point.
Water is a molecular compound with its lower boiling point. Molecular compounds have weaker covalent bonds.
What’s the difference between a covalent and an ionic bond? Be sure to give the overall charge of an ionic compound in your answer!
In an ionic bond, a transfer of electrons occur to form oppositely charged ions that are attracted to each other and form an ionic compound with a NEUTRAL CHARGE.
In a covalent bond, the electrons are shared between the atoms, so each atom has 8 valence electrons.
Explain why carbon monoxide (CO) is a polar molecule while carbon dioxide (CO2) is not.
The electrons are pulled more strongly by the oxygen atoms in both molecules; however, the oxygen atoms are pulling the electrons in opposite directions in CO2, so the forces cancel out and the overall molecule is non-polar.
Ammonium chloride is represented as NH4Cl, which is an example of a chemical ______________. This chemical is often used in instant cold packs.
In a chemical formula the positive ion is written ____________ (last, first, or in the middle).
Ammonia is an important substance for cleaning and making other substances used in fertilizers and cold packs. The chemical formula for ammonia is NH3. What does the “3” tell you about the compound?
There are 3 hydrogen atoms for every nitrogen atom.
What are the names of the following compounds: Na2O, Ba(NO3)2, and (NH4)2SO4?
Sodium oxide: Na2O
Barium nitrate: Ba(NO3)2
Ammonium sulfate: (NH4)2SO4
Write the chemical formulas for barium chloride and aluminum sulfate.
Barium chloride: BaCl2
Aluminum sulfate: Al2(SO4)3
When chemical bonds break and new bonds form a chemical _______ takes place.
A chemical reaction
In a chemical equation, what is written on the left side of the arrow and what is written on the right side? Which one is present at the end of the reaction?
Reactants (left), products (right)
Products- present after the reaction
What is the principle of the conservation of mass?
Mass is not created or destroyed.
How many acetylene (C2H2) molecules and oxygen gas (O2) molecules need to be present for the following reaction (think ratios):
2C2H2 + 5O2 2H2O + 4CO2? This reaction produces a fair amount of heat, so it is an ________________ change.
2 (C2H2) to 5 (O2); exothermic
Identify the type of reaction for each one below and balance the first chemical equation:
C12H22O11 C + H2O
Cu + 2AgNO3 2Ag + Cu(NO3)2
4Fe + 3O2 2Fe2O3
CaCl2 + Na2CO3 CaCO3 + 2NaCl
C12H22O11 12C + 11H2O (decomposition)
Cu + 2AgNO3 2Ag + Cu(NO3)2 (single replacement)
4Fe + 3O2 2Fe2O3 (synthesis)
CaCl2 + Na2CO3 CaCO3 + 2NaCl (double replacement)
As temperature ___________, the rate of a chemical reaction usually increases (since molecules are moving faster).
In sawmills, fine sawdust particles float through the air and fires can start easily. Explain why fires can start so easily in a place like a sawmill. Also, would there be a greater risk if there are more dust particles in the air (greater concentration)?
All of the sawdust is spread out (greater surface area), so the particles can more easily catch on fire due to more oxygen gas being in contact with them. Yes, a greater concentration speeds up the combustion reaction.
Salt is mostly sodium chloride, an ionic compound. Will it conduct electricity when melted or dissolved in water? Explain why or why not.
Yes, the ions in that ionic compound break apart so there are positive ions and negative ions moving around in the water, so an electric current can occur.
What is the relationship between the pressure and volume of a gas as well as between the temperature and volume of a gas?
As pressure increases the volume of a gas decreases (or vice-versa).
As temperature of gas increases, then the volume increases.
Describe solids, liquids, and gases in terms of their shape, volume, and movement of their particles.
Solids- def. shape and volume, particle sjust vibrate back and forth
Liquids- no def. shape, def. volume, particles roll about freely
Gases- no def. shape or volume, particles move randomly in all directions
Write the balanced chemical equation for the reaction of magnesium nitrate with potassium carbonate to produce magnesium carbonate and potassium nitrate.
Mg(NO3)2 +K2CO3 MgCO3 + 2KNO3