1.) subduction 2.) deep-ocean trench 3.) B
Answer:
D. Spain
Explanation:
Every other country on the list possesses nuclear weapons. The reason why Spain has none is that Spain plays a big role in supporting a world free of nuclear weapons. There are many activists and organizations in Spain that aim to raise awareness of the dangers that nuclear weapons pose to the global population. More than 90 Spanish parliamentarians are in favor to ban nuclear weapons.
A radioactive element with a half-life of 1,000 years, and starting mass of 20 grams, will need 2,000 years to decrease to 5 grams.
Explanation:
The radioactive elements all have a specific half-life. Each element's half-life is well known, and they are used by scientists of numerous fields as they are excellent for determining the age of a particular item, be it or organic or non-organic nature. In this case, we have a radioactive element with a half-life of 1,000 years, and starting mass of 20 grams.
The half-life basically means that half of the mass of an element is lost during a particular period of time. For the element in question we need to find out how much time will be needed for it to decrease to 5 grams. In order to get to the result, we just need to add 1,000 years on every decrease of half of the mass:
20/2 = 10
10/2 = 5
So in 1,000 years, the element in question will decrease to 10 grams, and in further 1,000 years (2,000 cumulatively) it will decrease to 5 grams.
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Answer:
Explanation:
The three main types of volcanoes are as follows:
1. Composite volcanoes: These are also called as strato volcanoes. These are steep and formed by the layers of ashes and lava. The eruption from these volcanoes is in the form of pyroclastic flow. The pyroclastic flow is in the form of superheated mixture which consists of rock dust, ash, and hot steam. These volcanoes can rise above the 8000 feet. These are found in the destructive plate margins. Example of these volcanoes include the Mount Fuji in Japan.
2. Shield Volcanoes: These volcanoes are low and they have gentle sloping sides. These are formed by the layers of lava. Their eruption of lava is non-explosive. These produces the fast flowing fluids that can flow to many miles. These can destroy the nearby surrounding regions can cause injury and even death. These volcanoes are found in the region of constructive boundaries and also at the volcanic hotspots. The examples of shield volcanoes include the Maunaloa on Hawaii.
3. Dome volcanoes: These are also called as acid lava cones as these emit acid which is much thicker than that of the lava. These have steeper sides as compared to the shield volcanoes. The lava is thick and sticky as a result of this it cannot flow to far region and it cools and solidifies. The example of dome volcanoes include the Puy de Dome of Auvergne, France.
Wind and erosion overtime
