A-through an optimistic viewpoint.
Answer:
Explanation:
“Southwest Asia: Pakistan, Afghanistan, Iran, Iraq, and the oil-bearing states bordering what now must tactfully be termed simply 'the Gulf,' all constituting a politically seismic zone of incalculable explosive potential.” Campbell later gave a similar definition: “'Southwest Asia' includes everything from the eastern
Answer:
C. plagioclase
Explanation:
From the magma silicate crystals are formed successively when the magma temperature reaches the typical melting temperature for each type of crystal. The first crystals formed at high temperatures can then change their composition or dissolve again. In this way the crystals already formed contribute their ions, molecules and atoms to magma and combine again forming new crystals whose melting temperature is lower than that of the first crystals formed. The new crystals are said to be stable at the lowest temperatures set now. These processes of change are called reactions. As several successive reactions occur as the magma temperature decreases the ordered series of reactions is called the BOWEN series in honor of the Canadian scientist who formulated this concept. There are two types of reactions, the continuous reaction and the discontinuous reaction.
<u>
By continuous reaction a crystal formed at high temperatures such as a plagioclase rich in the Ca2 +</u> component gradually varies its composition by replacing a portion of the Ca2 + ions with the Na + ions and a portion of the Al3 + ions with the Si4 + ions. To maintain its neutrality, the replacement of Ca2 + by Na + is coupled with the replacement of Al3 + by Si4 +. The series of continuous reaction starts from the plagioclase rich in Ca2 +, passes through several plagioclase of intermediate composition towards the plagioclase rich in Na +
Answer: Pastoral nomads
Explanation: Pastoral nomads are producers of food, and the size of their tribal or ethnic units increases accordingly. These groups raise livestock, and they move about within their established territory to find good pastures for their animals.
4.54 billion years<span>The "best" age for the Earth is based on the time required for the lead isotopes in four very old lead ores (galena) to have evolved from the composition of lead at the time the Solar System formed, as recorded in the Canyon Diablo iron meteorite. This "model lead age" is <span>4.54 billion years</span></span>