Investiga. El conflicto del Sahara

La colonia española del Sahara era ambicionada por sus vecinos, especialmente Marruecos, debido a su riqueza en fosfatos y pesca. En 1973 se había creado el Frente Polisario, una formación…

El signo

La lengua en la sociedad

End-of-unit activities - Animal reproduction

Reproduction is the only vital function that is not needed to keep an individual alive. It ensures the continuation of the species. Although sexual reproduction is a universal characteristic of animals,…

Write. Names and formulas (1)

Write the formula for each of these compounds: Nitrogen tribromide Sulphur dioxide Carbon tetrafluoride Lithium bromide

Calculate. Matter and its properties (1)

84 g of nitrogen reacts with hydrogen to form 102 g of ammonia. Calculate the mass of the hydrogen required for the reaction. g of hydrogen.

Final Autoevaluation T12 08 - Waves. Light and sound

Match the item to its characteristic of sound: 60 decibels   →    High pitched   →    A very loud sound   →    Piano   →    120 decibels   →    Bass…

Final Autoevaluation T12 10 - Waves. Light and sound

Indicate (Yes or No) for the characteristics of the shadow produced by a point light source: It has sharp edges   →    Two different areas of shadow are formed   →    Does it have the…

The rural problem

There is no doubt that, as I said, one of the greatest ills we suffer is the unequal distribution of land and that most of it is in the hands of the few (...). That the excessive extension of this…

The atom bomb dropped on Hiroshima

At 7.09 a.m. the air-raid alarm sounded and four American B-29 aeroplanes appeared in the sky. (…). At 7.31 a.m. the siren sounded to announce that the bombing was over. Thinking they were safe now,…