Thursday, 8 January 2015

Science for kids - Coloured flowers

This is quite a simple one. Grab some carnations (or other white flowers), a vase, some food colouring and water. Add a generous amount of colouring to the water (20-odd drops), add the flowers, and wait. It can take longer than a day, especially if you haven't quite added enough colouring, so be patient. Here are some shots we took of our red and blue flowers (I reckon you can be more impressive than this!):



The flowers turned blue quicker than red for me, and others have seen similar things (anyone know why?)

The science on display is the capillary action of the water - that is, how the flower drinks even without its roots. This ability draws water against the force of gravity up the stem and into the petals. It works because the water evaporating from the petals and leaves of the plant "pulls" water up the narrow tubes in the stem (the xylem) to replace that which is lost. The tubes need to be narrow so that the combination of the surface tension of the water (caused by cohesion in the water - how well it sticks to itself) and the adhesive forces between the water and the walls of the xylem are strong enough to lift the water against the force of gravity. The adhesive forces are proportional to the diameter of the tube, whilst the weight of the water is proportional to this diameter squared - hence a smaller diameter favours the adhesive forces.

Something funky to try is to split the stem and put one half in blue and the other in red. You can get multi-coloured flowers.

6 comments:

  1. It doesn't make any difference in the event that they are in your home or in the yard, in a pot with soil or in bricklayer container with stream shakes and water. Flowers have been a focal piece of our humankind all through the ages. beauty and the beast rose

    ReplyDelete
  2. One of the most beautiful of all the creatures that live in the oceans is the rare and very seldom seen venus flower basket. To the Japanese this is a symbol of eternal love and being happily married forever. A Venus flower basket is sometimes given as a wedding present in Japan because of this beautiful symbolism. Florisis Cluj

    ReplyDelete
  3. To know more about Chief Dr Lucky you can visit his website (https://chiefdrluckyherbaltherapy.wordpress.com/)
     
     A friend that suffered from Herpes and was cure with the help of this great herbal doctor Chief Lucky so i decided to contact him for help in getting rid of my families genital herpes virus 1/2 which i did and all i was told to provide was just some useful information and some materials used in preparation of the natural cure and that i did and now i am the happiest person on earth because i am writing this testimony of mine with joy and happiness in my heart to the whole world to know that natural remedy is real because i am a living testimony of Chief Lucky traditional herbal cure and i want you all to contact Chief Lucky via his email: chiefdrlucky@gmail.com or WhatsApp him +2348132777335 am sure he will help you too.

    ReplyDelete
  4. These exquisite flowers will commonly live for about seven days. Notwithstanding in the event that we are talking life span, scent and value I have discovered nothing better compared to lavender. floral wall

    ReplyDelete
  5. This is such a great resource that you are providing and you give it away for free. I love seeing blog that understand the value of providing a quality resource for free. visit this site

    ReplyDelete