Simple Atomic Structure,home learning

Simple Atomic Structure,home learning

Simple atomic structure for home learning

Atomic number, mass number and electron arrangement. Check your learning with a 30 second 5 question quiz

Atomic Number and Mass Number.

  • The atomic number is the number of protons in the nucleus of an atom.
  • In a neutral atom the numbers of protons (+) and electrons (-) are the same.
  • The mass number is the total number of protons and neutrons in the nucleus of an atom.


But wot about the electrons?

    • Electrons are arranged in cloud like shells around the nucleus.
    • Shells closest to the nucleus fill up with electrons first.
    • The first shell is full with two electrons.The second and third shells are full with eight electrons.
    • For the first twenty elements remaining electrons go in the fourth shell.


The sodium atom



  • the atomic number is 11. There are 11 protons in the nucleus and eleven electrons in the shells around the nucleus.
  • Two electrons go in the first shell, eight in the second and the remaining electron goes in the third shell.
  • The electron configuration for sodium is Na(2,8,1). This is enough information to understand how the first 20 elements in the periodic table react with each other,
quick quiz

Lake Tikitapu

Lake Tikitapu

Lake Tikitapu

The blue lake

Picture Perfect with a violent past.

Twenty minutes out of Rotorua on the Tarawera road lies picturesque Tikitapu. An undulating track meanders around the lake and it takes 1.5 hours to complete if you stop to admire the stunning views. 

The scenery is 20, 000 years in the making and each hill and cliff face marks a significant volcanic event.

The hill that looks like a cuddly neck collar worn on long haul flights exploded into life 21000 years ago and is a rhyolite dome. Rhyollite is a thick viscous lava that melts at around 800 degrees celsius. It is simply referred to as North Dome.




Smooth and rounded or a bit crumpled.

Depends on which side of the lake you find yourself.

North Dome on the eastern shore has a beautifully rounded sculptured look. The lava flows appear this way because they have been liberally dusted with tephra (literally anything that falls from the sky) Dutch masters used the same technique, adding layers of paint till they got it right.

It is a slightly different story on the other side of the lake.  The lava front cooled and solidified forcing the rest to back up and crumple leaving a noticeable rib structure more typical of rhyolite flows. This happened about 18000 years ago.


Tikitapu lies on the fringe of the Okataina volcanic centre.

Not far away, Mount Tarawera was the scene of New Zealand’s most violent eruption in the last 500 years.

A rhyolitic dome split apart with very  little warning. Earthquake tremors were first felt in Rototrua  about 12.30am on 10 June 1886. Around 2am basalt lava rather than the usual rhyolite began erupting from the central dome of Mount Tarawera. 

Two hours later pyroclastic eruptions were occurring on Taraweras three main peaks. 





Better than a selfie

This work was painted by Charles Bloomfield who was renowned for his meticulous attention to detail. We can be reasonably certain this is an accurate representation of events

Towards the right of the painting Bloomfield has caught the moment basaltic lava at over 1000 degrees Celsius came in contact with the hydrothermal system underneath the old lake Rotomahana.

Like dropping water on a BBQ hotplate with gas turned up max the instantaneous production of colossal volumes of steam resulted in a phreatomagmatic explosion.

What goes up must come down. The column of scoria ash mud and steam reached a height of 10 kilometres .

The catastrophic collapse of this column would have projected hurricane speed surges of scalding hot debris outwards from the base destroying everything in its path

New Zealand Journal of Geology and Geophysics

I. A. Nairn (1979) Rotomahana—Waimangu eruption, 1886: base surge
and basalt magma, New Zealand Journal of Geology and Geophysics, 22:3, 363-378, DOI:
To link to this article:






Caterpillar City

Caterpillar City

Tales From a Tiny Garden

Caterpillar City Crisis








Older Monarch caterpillars trash their environment leaving nothing for the younger generation….

Monarch caterpillars are voracious eating machines. They eat swan plants exclusively and will completely trash a large plant in days. Big caterpillars survive while smaller ones starve to death as the availability of leaves dwindles. Fully grown caterpillars will stand up on their rear legs and headbutt each other over a juicy leaf when supply is short.

Despite completely trashing their environment, leaving nothing but green twigs for younger generations Monarch caterpillars still have a swan planet B.

Step 1. Pupate, and hide away in a chrysalis for about 10 days. 

Step 2. Bash your head against the Chrysallis to knock a hole in it. Squeeze out carefully and pump your wings up before flying off to another swan planet.

Luckily we are a bit smarter than Monarch caterpillars and have a plan for saving Lake Rotorua. It’s the rest of the planet I sometimes worry about.

Lake Rotorua Nutrient Management – Plan Change 10.



Attack of the killer wasps

Attack of the killer wasps

Tales From a Tiny Garden

Attack of the killer wasps















Chemical warfare in a tiny garden in Rotorua sitting above the lake not far from the CBD.

Chemical warfare in a tiny garden in Rotorua.

A sunny afternoon relaxing in suburban Rotorua, above the lake not far from the CBD. Bad things happen in tiny gardens.

Early summer and dark chemical processes are at work in the bright sunlight. Swan plants are producing and stockpiling deadly molecules in their sap and leaves. A chemical defence system designed to kill insects foraging for food.  The main components of this molecular arsenal are cardenolide glycosides, steroids with an attached sugar structure. These toxins can induce cardiac arrest.

Monarch caterpillars and butterflies are immune to these poisons. Caterpillars voraciously devour swan plant leaves. In the process they hijack the plant’s chemical defence system for use against predators. Birds associate becoming sick with a diet of brightly coloured caterpillars or butterflies and drop them from their diet.


Attack of the killer wasps.

Asian paper wasps are very determined predators of monarch caterpillars and are unaffected by the cardenolides. Wasps need protein for nest construction and developing larvae in spring and early summer. Caterpillars are a good source of protein at this stage.  

I watched wasps make their way through dense foliage in relentless pursuit of their prey. Monarch caterpillars appear to understand the danger and some seek refuge amongst the spines of the swan plant seed pods. The aerial bombardment is relentless and a plant can be completely stripped of the caterpillar population in a day. The big mature caterpillars are a favourite target and I have seen them stand up on a leaf in a forlorn attempt to beat off a merciless attacker.

The assault has a number of stages

  • The wasp lands on the caterpillar and probably stings it
  • The wasp starts to skin the caterpillar while it is still moving. It bites through the skin which rolls back to reveal the underlying body.
  • It may move the whole carcass to a more stable location where it slices it up into manageable chunks to fly away with.

In late summer when the need for protein has diminished, wasps change their diet, feasting instead on the nectar produced by swan plant flowers.

Relationship beteeen steroids and cardenolide glycosides

oleandrin a cardenolide glycoside

oleandrin a cardenolide glycoside

 Oleandrin is one of the cardenolide glycosicdes found in swan plants. The structure hanging on to the bottom left of the steroid skeleton is based on a sugar unit hence the glycoside in the name.

Attack of the killer Mantis

Attack of the killer Mantis

Tales From a Tiny Garden

Attack of the killer Mantis












A sunny afternoon relaxing in suburban Rotorua. Owhata, above the lake not far from the CBD. Bad things happen in tiny gardens.

A sunny afternoon, the perfect picture, where’s my camera when I need it? A white butterfly flutters gently on a pot plant decorating the fence line beside the tree nursery. It is rushing to fill the the tank with carb rich nectar. It’s dangerous to park here for too long. Something is amiss? The delicate wings are beating with too much urgency. Maybe two insects are locked in an embrace, rolling on the soft red petals. I need a closer look or perhaps a visit to Specsavers.

My tiny garden is a beautiful savage microcosm.The terrified butterfly is held in the death grip of a Praying Mantis. Two raptor arms encircle wings and abdomen. Pointy restraining  attachments on the legs gouge the insect’s abdomen as it struggles to escape. Sharp teeth slice effortlessly through brain and neck ending the brief resistance.

After five minutes of carnage all that remains of the butterfly is a single surgically amputated winglet that escaped  butchery, floating away on the gentle breeze.

The video was taken using a Canon EOS 60D camera. Invidual clips were editied together using Gopro Studio.

For further horrors in a savage garden: Attack of the Killer Wasps  and Attack of the Killer Ladybirds

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