Presentation is loading. Please wait.

Presentation is loading. Please wait.

Honors Biology Chapter 2

Similar presentations

Presentation on theme: "Honors Biology Chapter 2"— Presentation transcript:

1 Honors Biology Chapter 2
The Chemistry Of life

2 The Nature of Matter Essential Question: How would you explain the relationship between atoms, elements, and compounds?

3 Atoms smallest unit of matter
each element has its own unique # of protons (atomic #)

4 Elements Only ~ 24 elements found in living things 4 most abundant:
Oxygen Carbon Hydrogen Nitrogen

5 Isotopes atoms of same element with different # of neutrons
#p + #n = atomic mass (mass #)

6 Radioactive Isotopes some isotopes have unstable nuclei so they undergo “decay”

7 Chemical Cpds compound: substance formed by chemical combination of 2 or more elements in definite proportions cpd has different properties than elements alone had

8 Chemical Formulas

9 Chemical Bonds Atoms form chemical bonds with other atoms to ________________. The 2 main types of bonds are ________ and ____________.

10 Types of Bonds

11 Chemical Bonds share valence e- unequal sharing e- Covalent Bonds
Polar Covalent Bonds share valence e- unequal sharing e-

12 Ionic bonds transfer of e-  atom with a charge (ion)
(+) ions = cations (-) ions = anions opposite charges attract charges must be balanced stronger bonds than covalent

13 van der Waals Forces Because atoms do not share e- equally, there are polar bonds This causes the (+) end of one molecule to be attracted to the (-) end of another molecule This attraction is called van der waals forces Very weak compared to covalent bonds but are still able to hold molecules together

14 Van der Waals Forces in action

15 What type of bond is shown here?

Download ppt "Honors Biology Chapter 2"

Similar presentations

Ads by Google