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Bell Ringer. 1) Which nucleus below belongs to the element on the right? (red = proton, yellow = neutron) a) b) c) d).
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Bell Ringer 1) Which nucleus below belongsto the element on the right?(red = proton, yellow = neutron) a) b) c) d)
2) Your friend stands on a scale and proclaims that his mass is 170 pounds. You answer:a) That is not your mass. Your mass is how much space you take up. 170 pounds is your weight b) Your mass is equal to the pressure of gravity pulling on you. That is why your mass is 170 pounds.
3) There are four elements associated with life – they make up 90% of all living things. Which answer lists them?a) Carbon, Nitrogen, Phosphorus, Magnesiumb) Carbon, Oxygen, Hydrogen, Siliconc) Nitrogen, Beryllium, Hydrogen, Oxygend) Hydrogen, Oxygen, Nitrogen, Carbon
The pictures below best represent: a) neutrons b) isotopesc) protonsd) atoms
Still Chemistry... • Most elements do not exist solely as that element. • Atoms of most elements will readily combine with other atoms to form compounds.
Still Chemistry... • Chemical compounds are found all around us. • Do you recognize these common chemical compounds? - NaCl = - C12H22O12 = - CH2CH3OH = - NaOCl =
Still Chemistry... • Chemical compounds are found all around us. • Do you recognize these common chemical compounds? - NaCl = Table Salt - C12H22O12 = - CH2CH3OH = - NaOCl =
Still Chemistry... • Chemical compounds are found all around us. • Do you recognize these common chemical compounds? - NaCl = Table Salt - C12H22O12 = Sucrose (Sugar) - CH2CH3OH = - NaOCl =
Still Chemistry... • Chemical compounds are found all around us. • Do you recognize these common chemical compounds? - NaCl = Table Salt - C12H22O12 = Sucrose (Sugar) - CH2CH3OH = Mouthwash - NaOCl =
Still Chemistry... • Chemical compounds are found all around us. • Do you recognize these common chemical compounds? - NaCl = Table Salt - C12H22O12 = Sucrose (Sugar) - CH2CH3OH = Mouthwash - NaOCl = Bleach
Still Chemistry... • The chemical and physical properties of elements change when they become compounds. • Sodium (Na) is a solid that reacts explosively with water.
Still Chemistry... • The chemical and physical properties of elements change when they become compounds. • Sodium (Na) reacts explosively with water. • Chlorine (Cl) is a poisonous gas
Still Chemistry... • The chemical and physical properties of elements change when they become compounds. • Sodium (Na) reacts explosively with water. • Chlorine (Cl) is a poisonous gas • But, together, they make table salt (NaCl) + =
Still Chemistry... • Most atoms are not stable in their natural state, so they react with other atoms (forming compounds) to become more stable.
Still Chemistry... • Most atoms are not stable in their natural state, so they react with other atoms (forming compounds) to become more stable. • Chemical compounds are formed by atoms joining together. • These atoms are held together by chemical bonds.
Still Chemistry... • Most atoms are not stable in their natural state, so they react with other atoms (forming compounds) to become more stable. • Chemical compounds are formed by atoms joining together. • These atoms are held together by chemical bonds. • Bonding is all about the electrons!
Chemical Bonds... • There are two types of chemical bonds:
Chemical Bonds... • There are two types of chemical bonds: Covalent Bonds Ionic Bonds
Covalent Bonds • Covalent bonds – a bond that forms between two atoms that share one or more electrons.
Covalent Bonds • Covalent bonds – a bond that forms between two atoms that share one or more electrons. • Water is made up of one oxygen atom and two hydrogen atoms held together by covalent bonds.
Covalent Bonds • An atom is stable when it has 8 electrons in its outermost shell • The only exception is hydrogen, which is stable with 2 electrons.
Covalent Bonds • Based upon this Rule of 8, an oxygen atom with six electrons will gladly bind to two hydrogen atoms to obtain a total of eight electrons.
Ionic Bonds • Ionic bonds – a bond that forms between two charged atoms in which electrons are transferred from one atom to the other.
Ionic Bonds • Ionic bonds – a bond that forms between two charged atoms in which electrons are transferred from one atom to the other. • Sodium (Na) has one electron in its outer shell. • Chlorine (Cl) has seven electrons in its outer shell.
Ionic Bonds • Because both atoms want to have 8 electrons in their outer shell, sodium gives away its 1 electron.
Ionic Bonds • Because both atoms want to have 8 electrons in their outer shell, sodium gives away its 1 electron. • Both atoms now have 8 electrons in their outer shells.
Ionic Bonds • This sharing of electrons, though, causes the atoms to become charged. • Because sodium lost an electron, it gains a positive charge. • Chlorine, which gained an electron, is now negatively charged. • A charged atom is called an ion.
Ionic Bonds • The positive charge of the sodium and the negative charge of the chlorine attract each other, creating the ionic bond.
Ionic Bonds • The positive charge of the sodium and the negative charge of the chlorine attract each other, creating the ionic bond. • “Opposites attract!” • Example: balloon and hair
Determining the Number of Electrons 1 2 8 1 234567 3 4 5 6 7 Red numbers = # of electrons Blue numbers = # of orbitals (circles)
A “Bonding” Experience • Everyone will be assigned an element. • Remember (unless you are hydrogen), that you need a total of 8 electrons in your outer shell to be stable. • Your job is to find another student (or more) in the room to bond with so that you both are stable. • You will have thirty seconds to do so. Any student not “bonded” will be out.
Creating Chemical Compounds Make some Hydrochloric Acid (HCl)
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) • First, identify which two elements are part of this compound.
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) • First, identify which two elements are part of this compound. Hydrogen – HChlorine - Cl
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 2) Draw Hydrogen
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 2) Draw Hydrogen 1 2 8 1 234567 3 4 5 6 7
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 2) Draw Hydrogen
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 3) Draw Chlorine
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 3) Draw Chlorine 1 2 8 1 234567 3 4 5 6 7
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 3) Draw Chlorine
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 4) Put them together by sharing an electron
Creating Chemical Compounds Make some Hydrochloric Acid (HCl) 4) Put them together by sharing an electron
Chemistry Practice 1) Make Water (H2O)
Chemistry Practice 1) Make Water (H2O) 1 2 8 1 234567 3 4 5 6 7