ch2 atoms&molecules
TRANSCRIPT
![Page 1: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/1.jpg)
Atoms and MoleculesBasic units of EVERYTHING!
![Page 2: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/2.jpg)
Which of these is true?
1 2 3
3%
82%
15%
1. “Atom” and “molecule” mean the same thing.
2. Atoms are made of molecules.
3. Molecules are made of atoms.
![Page 3: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/3.jpg)
What is the smallest structure in this list that can be seen with an ordinary desk microscope?
1 2 3 4
35%
18%
10%
38%1. Cells.2. Cell nucleus.3. Atoms.4. Chain molecules,
such as proteins.
![Page 4: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/4.jpg)
Atoms
![Page 5: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/5.jpg)
In our model of scale, remember that the BB represented an atom.
![Page 6: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/6.jpg)
As a class, identify the atoms represented here and label the sub-atomic particles.
Electrons
ProtonsNeutrons
Hydrogen Helium
![Page 7: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/7.jpg)
What elements are represented here? Use the Periodic Table on the wall to identify these atoms.
What does the term “valence shell” mean? Label the valence shell on each of these.
Carbon OxygenPhosphorous Calcium
![Page 8: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/8.jpg)
IonsLoss or gain of
an electron makes an
atom into an ion.
+
-
-Gaining an electron makes a positive or
negative ion?
Losing an electron makes
a positive or negative ion?
![Page 9: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/9.jpg)
IsotopesAtoms that gain or lose
a neutron become isotopes.
Radioactive isotopes are used in medicine for imaging (such as
PET scanners).
![Page 10: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/10.jpg)
Why is this important?• Each element has distinct
properties: color, melting point, reactivity, etc.
• The basic atomic structure of each element determines that element’s properties. Change the structure, and you have an entirely different element.
![Page 11: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/11.jpg)
Which of these is found in the nucleus of an atom?
1 2 3 4
78%
6%6%11%
1. Protons2. Electrons3. DNA4. Depends on the
atom
![Page 12: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/12.jpg)
An ion is an atom that has lost or gained:
1 2 3 4
83%
11%
0%6%
1. An electron2. A proton3. A neutron4. Any sub-atomic
particle
![Page 13: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/13.jpg)
T or F: An atomic nucleus and a cell nucleus are about the
same size.
1 2 3
33% 33%33%
1. True2. False3. Depends on which
cell and which atom.
![Page 14: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/14.jpg)
Atoms bond together• Molecules are made up of atoms
bonded together.• The structure of an individual atom
determines:• Whether the atom can form
bonds.• How many other atoms it can
bond to.
![Page 15: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/15.jpg)
In our model of scale, remember that the marble represented a
small molecule, such as glucose.
![Page 16: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/16.jpg)
How many atoms can each of these atoms
bond with?
How do we know?
![Page 17: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/17.jpg)
Fill in the blank column with number of covalent bonds formed by each atom.
14
32
52
![Page 18: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/18.jpg)
Ionic Bonding
![Page 19: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/19.jpg)
Ionic substances tend to form crystaline lattices rather than distinct molecules.
![Page 20: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/20.jpg)
Covalent BondingCo = together
valent = valence shells
The hydrogen atom. How many bonds can it form?
![Page 21: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/21.jpg)
Covalent bondingA hydrogen molecule. How many hydrogen atoms are involved?
Can there be more? Why or why not?
![Page 22: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/22.jpg)
• Describe in your own words the difference between ionic and covalent bonding.
WORK
TOGETHER
![Page 23: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/23.jpg)
Covalent Bonding
![Page 24: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/24.jpg)
Polar bonding between atoms produces a polar molecule, which has areas with slightly positive
or slightly negative charges.
![Page 25: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/25.jpg)
• Describe in your own words the difference between nonpolar and polar covalent bonding
WORK
TOGETHER
![Page 26: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/26.jpg)
When atoms bond together, they make:
1 2 3 4 5
20% 20% 20%20%20%
1. Cells2. Molecules3. More atoms4. Ions5. Isotopes
![Page 27: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/27.jpg)
Which of these is true?
1 2 3 4
0% 0%6%
94%1. Molecules and cells are about the same size.
2. Molecules are much smaller than cells.
3. Cells are much smaller than molecules.
4. “Cell” and “molecule” mean the same thing.
![Page 28: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/28.jpg)
Which kind of bond between atoms creates a distinct
molecule?
1 2 3
44%
17%
39%1. Ionic bonding2. Covalent bonding3. Both ionic and
covalent bonding.
![Page 29: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/29.jpg)
Which is true about polar covalent bonding?
1 2 3
6%0%
94%1. An electron is
shared equally between two atoms.
2. An electron is shared unequally between two atoms.
3. An electron leaves one atoms and becomes part of another.
![Page 30: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/30.jpg)
True or false? The atomic “shell” is a cell membrane.
1 2
88%
13%
1. True2. False
![Page 31: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/31.jpg)
Why is polarity so important?
Salt dissolves in water. Oil does not.Why?
What will oil dissolve in? Why?
![Page 32: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/32.jpg)
• Is a water molecule in the gas phase larger than, smaller than, or the same size as a water molecule in the solid phase?
• Describe what happens to water molecules as liquid water evaporates.
WORK
TOGETHER
![Page 33: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/33.jpg)
Molecules bond together
Weak attractive forces between molecules are called hydrogen bonds.
![Page 34: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/34.jpg)
Here, sugar (a polar substance) is in solution with water (also polar). Mark where the hydrogen bonds will form.
![Page 35: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/35.jpg)
Hydrogen bonding occurs:
1 2 3 4
25% 25%25%25%1. Between atoms.2. Between
molecules.3. Between cells4. Between any
particles.
![Page 36: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/36.jpg)
Hydrogen bonding is:
1 2 3
33% 33%33%1. Strong and difficult to break, like polar covalent bonding.
2. A strong attraction between charged ions, like ionic bonding.
3. A weak attraction between polar molecules.
![Page 37: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/37.jpg)
Properties of Water• Water is:
• Cohesive• Adhesive• A “universal solvent”
• Water also has:• A high specific heat• A high heat of vaporization
![Page 38: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/38.jpg)
pH is a ratio between H+ and OH- ions in solution.
![Page 39: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/39.jpg)
• One unusual property of water is that it is less dense in the solid stage than in the liquid stage, which causes ice to float. Why does water become less dense as it freezes? Use what you learned about hydrogen bonding between molecules.
WORK
TOGETHER
![Page 40: Ch2 atoms&molecules](https://reader034.vdocuments.site/reader034/viewer/2022052313/58f12bc41a28abee1f8b4571/html5/thumbnails/40.jpg)
Recap
1.What is the difference between atoms and molecules?
2.What is the difference between ionic bonding and polar covalent bonding?
3.How is polarity related to pH?