On
30 June 1808 Davy reported to the Royal Society that he had
successfully isolated calcium. Here are 10 things you might not know
about calcium:
It’s
an alkaline metal which is reactive and soft enough to be cut with a
sharp knife.
Its
chemical symbol is Ca and its atomic number is 20. Its Melting point
is 1115 K (842 °C, 1548 °F) and its Boiling point is 1757 K (1484
°C, 2703 °F).
It
is the fifth most abundant element in Earth's crust, and the third
most abundant metal, after Iron and Aluminium. It’s also abundant
on the moon.
The
name derives from Latin calx, or calcis, meaning "lime", a
substance obtained from heating limestone. Which makes sense because
the most common calcium compound on Earth is calcium carbonate,
found in limestone and fossils. Although calcium wasn’t isolated
until 1808, its compounds have been commonly used as building
materials since ancient times. Egypt’s Pyramids were built using
limestone blocks.
Calcium
is the most abundant of the metallic elements in the human body. The
average adult body contains about 1 kg or 2 lb of calcium, 99% of
which is in the bones and teeth. In fact, calcium is essential for
healthy bones and teeth and also plays a part in other bodily
functions. It is vital to the health of the muscular, circulatory,
and digestive systems.
Foods
containing calcium include: Milk, Yogurt, and Cheese; canned
sardines and salmon with bones; kale, Broccoli, and Chinese cabbage
(bok choi); and grains, such as breads, pastas, and unfortified
cereals. These contain relatively small amounts of calcium but as
foods people eat a lot of are nevertheless an important source.
Vitamin D is necessary to help the body absorb calcium. According to recent
studies, calcium in vegetables is more easily absorbed by the human
body than calcium in milk.
Calcium
loss occurs at a higher rate during the night, with women losing
more as they sleep than men.
The
major producers of calcium are China, Russia and the United States.
Canada and France are also among the minor producers. Most of the
world's extracted calcium is used by the United States.
The
largest use of metallic calcium is in steel making, due to its
strong chemical affinity for Oxygen and sulphur.
Character
birthday
Lexie
Worthington, American snowboarding champion and model. On a
photo-shoot in Galorvia, where she was promoting her new brand of
snowboarding gear, she met Hector Kostellov, and went on several
dates with him before returning to the US, unaware of his status as a
member of the Galorvian royal family. He followed her to America and
they became an item. She now lives in Galorvia. She appears in Tale
of Two Sisters.
A Tale of Two Sisters
During a battle with supervillains, a horrific accident leaves the Warner family with no option but to believe their youngest daughter, Jessica, is dead. It doesn't occur to them that the bad guys could, or would, save her.
Jessica wakes up with no memory of who she is or how she came to be on a space station with two bionic legs, a bionic arm and a bionic eye. She is told her family abandoned her and is sent back to Earth with a mission - to kill them. While Jessica wants to kill her family, along with the twin boys who once rejected her, she knows what the Alliance of Supervillains are asking her to do is a suicide mission. She decides to get her revenge in her own way.
As Jessica puts the first part of her revenge plan in motion, she finds herself with an agonising decision to make. Before she can decide, the Alliance come for her, determined to make her do their bidding. This time, it's the Alliance who leave her, crippled and at the mercy of the Warner family, who have no idea who the Alliance's Black Rose really is.
Jessica finds herself having to re-think her decisions in light of what she now learns about her family, the Alliance, the twins, and herself. It would appear the Alliance have left her with an unwanted and permanent reminder of her time with them. Or have they?
Jessica's older sister, Jill, knows her destiny is to be a doctor and specialise in bionics and genetic variant medicine. She is also hopelessly in love with Christopher, Crown Prince of Galorvia. Can their romance survive the lies Christopher told her when they were both at school, an unplanned pregnancy and Sophie, the wannabe princess who comes between them?