• Articles
  • Activities
  • Interactives
  • Videos
  • Teacher PLD
  • Primary
  • Secondary
ARTICLE

How elements are formed

Our world is made of elements and combinations of elements called compounds. An element is a pure substance made of atoms that are all of the same type. At present, 116 elements are known, and ...

READ MORE
STAR
ARTICLE

Non-Newtonian fluids

Many people have heard of Sir Isaac Newton. He is famous for developing many scientific theories in mathematics and physics. Newton described how ‘normal’ liquids or fluids behave, and he ...

READ MORE
STAR
ARTICLE

Absolute dating

Geologists often need to know the age of material that they find. They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of ...

READ MORE
STAR
ARTICLE

Relative dating

Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence. The method of reading the order is called stratigraphy (layers of rock are called strata) ...

READ MORE
STAR
ARTICLE

Development of the periodic table

Although elements such as gold, silver, tin, copper, lead and mercury have been known since earliest times, the first scientific discovery of an element occurred in 1649. Hennig Brand, a German ...

READ MORE
STAR
ARTICLE

States of matter

Anything that has mass is made up of matter – an all-encompassing word for atoms and molecules that make up our physical world. We describe this matter as existing in states (sometimes referred ...

READ MORE
STAR
ARTICLE

Soil properties

All soils contain mineral particles, organic matter, water and air. The combinations of these determine the soil’s properties – its texture, structure, porosity, chemistry and colour. Soil ...

READ MORE
STAR
ARTICLE

What are ceramics?

A ceramic is an inorganic non-metallic solid made up of either metal or non-metal compounds that have been shaped and then hardened by heating to high temperatures. In general, they are hard ...

READ MORE
STAR
ARTICLE

Ocean density

The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. Salinity, temperature and depth all affect ...

READ MORE
STAR
ARTICLE

Ocean temperature

The temperature of the ocean determines what form the water takes. Most of the ocean is liquid water, but if it gets cold enough, it turns to solid ice, or if it gets hot enough, it can pass into ...

READ MORE
STAR
ARTICLE

What is clay?

Since the earliest times, humankind has had a close association with clay. From use as a building material, in pottery, for treating human digestive ailments to a multitude of industrial uses ...

READ MORE
STAR
ARTICLE

Chemical reactions and catalysts

A chemical reaction involves a chemical change, which happens when two or more particles (which can be molecules, atoms or ions) interact. For example, when iron and oxygen react, they change to ...

READ MORE
STAR
ARTICLE

Bone and tooth minerals

The minerals found in human teeth and bones that give them their hardness and strength belong to a group of minerals called biological apatites. The apatites found in bone, tooth enamel and tooth ...

READ MORE
STAR
ARTICLE

Light and telescopes

The universe is full of amazing things, but we need help to see most of them. There are many types of light that our eyes cannot see, so we use instruments, such as telescopes, that can detect ...

READ MORE
STAR
ARTICLE

Viscosity

If you poured some water down a slope, it would flow freely and quickly, but what about if you repeated the process with honey? Can you imagine how honey would flow down a slope? Sticky oozy ...

READ MORE
STAR
ARTICLE

Metals, alloys and metal compounds

From titanium implants to new superconducting alloys to useful metal compounds, we are increasingly dependent on metals. Without metals, modern civilisation would literally collapse. About 80% of ...

READ MORE
STAR
ARTICLE

Date a dinosaur

Dinosaurs used to live in New Zealand. We know this because their fossils have been found in a few places. The fossils of a number of different dinosaurs were found at the Mangahouanga Stream, in ...

READ MORE
STAR
ARTICLE

The rock cycle

The Earth is an active planet. Earthquakes shake and volcanoes erupt. Sections of the crust are on the move. Mountains push up and wear down. These and many other processes contribute to the rock ...

READ MORE
STAR
ARTICLE

Seeing atoms

Nanotechnology is possible partly because tools have been developed to ‘see’ particles of matter a nanometre (nm) across, or smaller. That’s less than a billionth of a metre. When the idea of ...

READ MORE
STAR
ARTICLE

Lightning explained

Lightning is a large-scale natural spark discharge that occurs within the atmosphere or between the atmosphere and the Earth’s surface. On discharge, a highly electrically conductive plasma ...

READ MORE
STAR
ARTICLE

Distances in space

Distances in space are really, really big. The Voyager 1 spacecraft is heading out of our Solar System at 62,000 km per hour, but even at that speed, it would take it 77,000 years to reach the ...

READ MORE
STAR