Changes in the skills base and knowledge our students need require new learning goals; these new learning goals change the relationship between assessment and instruction. Teachers need to take an active role in making decisions about the purpose of assessment and the content that is being assessed.
Titanite, or sphene (from the Greek sphenos (ÏÏÎ·Î½Ï), meaning wedge), is a calcium titanium nesosilicate mineral, Ca Ti Si O 5.Trace impurities of iron and aluminium are typically present. Also commonly present are rare earth metals including cerium and yttrium; calcium may be partly replaced by thorium.ue depends on Fe content, with low Fe content causing green and yellow colours, and high Fe content causing brown or black hues. Zoning is typical in titanite. It is prized for its exceptional dispersive power (0.051, B to G interval) which exceeds that of diamond.
The chemical formula indicates how many atoms, and of what type, are in the chemical. For example, the chemical formula of water, H2O, shows that there are two hydrogen, and o â¦ ne oxygen, atoms in the molecule.t shows the chemical makeup of a substance using the chemical symbols of the elements in that substance. Hydrochloric Acid is made up of Hydrogen and Chlorine, expressed at H â¦ Cl. Water is made up of 2 hydrogen atoms and an oxygen, expressed as H2O.