Charcoal Set

Posted in art supplies on 08/05/2009 03:57 am by admin

Charcoal Set

How to Set Up a Terrarium

Once set up a plant terrarium requires very little maintenance and brings the pleasures of a greenhouse to your patio or home. If your terrarium also has reptiles it is called a reptarium. One with standing water is called a vivarium.

A terrarium would be a good choice if you don't have time for maintenance or if you have cats that love to nibble on your house plants! These miniature self contained mini greenhouses efficiently recycle moisture. The plants draw water from the soil which is released into the terrarium atmosphere by transpiration, condenses on the glass walls and returns to the soil. Occasional top ups are all that is needed to replace the small amount of water lost through the cap.

Terrarium History

Nathaniel Ward, an amateur botanist, made the first terrarium in 1827. He became concerned about the notorious pollution present in London air at that time on the butterfly cocoons he was studying he placed them in glass jars to protect them. After a few days he found ferns happily growing in his glass jars and realised the glass jars were ideal environments for growing moisture loving plants. His idea spread rapidly and terrariums became very popular especially for preserving exotic plant specied brought to England from abroad.

Choosing Plants

Suitable plants for your terrarium are those that are moisture loving and do not grow too big. The location where you will place the terrarium will dictate the amount of natural lighting that it receives and plants can be chosen accordingly. For a terrarium receiving low levels of natural light choose mosses, lichens and ferns. More choices are available for terrariums receiving moderate to good natural light including butterwort, Irish moss, philodendron, pitcher plants, jade plants, Venus fly traps and asparagus ferns. Flowering plants, such as African violets and geraniums, in a larger terrarium, can also be included. Terrariums should not be placed in direct sunlight. You can also add other decorative items such as terrarium (or aquarium) ornaments, driftwood or pine cones. Natural objects should be regularly inspected as the moist conditions can lead to rotting.

Setting up a Terrarium

Add a thin layer of gravel or pebbles to provide drainage covered with some activated charcoal which can be brought from garden centers or aquarium shops. The charcoal will help keep the air inside the terrarium clean. The next layer is sphagnum moss which will keep the next layer, the soil layer, in place. Special mixes of soil for terrariums can be used or use a mixture of two parts potting compost, one part coarse builders sand and one part leaf mold. Beach sand contains impurities that can be harmful to the plants and should not be used.

For a terrarium with live animals add a shallow dish of water. Now add the plants. Depending on how the terrarium will be viewed you can arrange the plants. For a terrarium that will be viewed from all angles the tallest plants should go in the middle with the smaller plants around the edges. If the terrarium will only be viewed from one side the tallest plants can go at the back with the smallest in the front. Be sure to keep the leaves away from the glass walls as moisture on the walls will drip onto the leaves and cause them to rot.

Add any decorations, add water to the soil and close the lid.

Maintenance

Inspect the terrarium regularly to check the moisture levels. If it appears too dry use a mister to add water but do not over water or the plants could rot. For a plant terrarium nothing more is needed.

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For more information on terrariums, terrarium plants and some good deals on new and used plant and reptile terrariums visit
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and
Cheap Reptile Terrariums

How many 14C atoms are in a charcoal sample that has a decay rate of 3500 desintergrations per minute?

14C , T 1/2 = 5730 yr. how do you set this up?

The activity (= number of decays per unit time) of a sample is proportional to the number of radioactive atoms it contains:
A = -dN/dt = λ∙N

So the number atoms in the sample is
N = A/λ

Decay constant λ and half life are related as:
λ = ln(2) / t½

Hence:
N = A ∙ t½ /ln(2)

In order to get consistent units for time convert half life to minutes:
t½ = 5730y = 5730 ∙ (365∙24∙60)min = 3.012×10⁹min

N = 3500min⁻¹ ∙ 3.012×10⁹min / ln(2)
= 1.521×10¹³

Faber-Castell :: PITT monochrome charcoal set