21. Rocks Become less dense when they melt.
23. Intraplate Setting
24. The Lithosphere
25. Divergent
26. For this one i would think it would be molten rock which is Magma which is in volcanoes so B. Active Volcanoes
The correct option is Rocks become less dense when they melt
The density of rocks get less when they are in molten form. Density is equal to mass per volume so in solid form the volume is reduced but when the volume increases in liquid form the density decreases that is why we can say that in molten form rocks have less density.
The correct option is D. convergent oceanic-continental plate boundary
When oceanic crust comes closer to continental crust, the denser oceanic plate plunges beneath the continental plate which is a process called subduction. This process occurs at the oceanic trenches inside the ocean. The rocks inside them melt and produce magma which is a hot material and then this magma rises and erupts, creating volcanoes. The yellow stone national park is associated with the same formation of tectonic phenomenon.
The earth's rigid outer layer, consisting of the crust and uppermost mantle, is called the Lithosphere
The lithosphere is solid and outer part of the Earth’s surface. This part includes the brittle upper portion of the mantle and the crust which is the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphe below. It extends to a depth of about 60 mi (100 km). It is broken into about twelve separate, rigid blocks, or plates.
The type of plate boundary where plates move apart, resulting in upwelling of material from the mantle to create is called Divergent boundaries
Divergent boundaries are present in the middle of the ocean. They contribute to seafloor spreading. When plates made of oceanic crust pull apart each other, a crack in the ocean floor appears from which the magma snoozes up from the mantle and fill in the space between the plates.
The correct option is D. Electromagnetic radiation
We know that there are many radioactive minerals present inside the earth. When these radioactive substance decay or produce radioactive radiation they melt the rocks in their surroundings. These rocks are then snoozed out by the area where the surface of the earth is comparatively soft. These areas are basically the volcanoes on the surface of earth. So we can say that the source of heat is electromagnetic radiations.
