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1

What had a higher CEC between tetrahedra and octahedra?

Octahedra

2

What dictates the strength of molecules attraction to eachother?

Size of the valence shell

3

What is a factor in isomorphic sub?

Atomic radius. Number of subatomic particles in element determine size.

4

What is the anion exchange capacity?

Area surrounding cation exchange sites where anions are attracted to adsorbed hydrogen and cations.

5

What is the diffused layer?

The layer of cations that surround clays, attached to the CEC

6

What is the second diffused layer

Anions that surround the diffused layer due to their attraction to the cations in the diffused layer.

7

What determines a soils CEC

Relative proportion of humus to Clay

8

What kind of Clay is bentonite?

A smectite, therefor expansive Clay

9

How much surface area in 1 g Clay

10m2 to 800m2

10

What is cation exchange capacity?

Measure of a soils capacity to carry H+ in adsorption layer

Measured in mg H in 100 g soil

11

How can lime help improve soils?

Lime displaces additional acidifying elements on CEC to make room for nutrients like NPK

12

What are bases when referring to CEC

All cations other than H Fe and Al

13

How does al+++ get into Si tetrahedrons?

Similar in size to silica but has a higher valence.

14

Does isomorphic replacement happen In octahedrons?

Yes, aluminum can be replaced by Mg or Fe

15

What is the origin of smectites?

Volcanic rock

16

What soil order results from high smectite content

Vertisols - due to vertical fracturing allowing OM to penetrate soil profile

17

What things limit the storage capacity of clays

Size of lattice

Isomorphic substitution

Type of Clay