Conventional volcanoes are known to erupt after pressure builds up from new magma flowing into the magma chambers that lie below the vents on the Earth's surface.
First convert the 112 km/hr ratio into m/s (meters per second). To do this you multiply 112 km with 1000 m/km (since there's 1000 m in one km). You get 112000 m. Then multiply 1 hr with 60 min/hr (since there's 60 min in one hr. You get 60 min, but you want seconds, so multiply 60 min with 60 s/min to get 3600 s. There you go! Your answer is the speed of 112000m/3600s, but you can simplify that to 31.11m/s (since the answer should be in ? meters per 1 second.
Also, the "100-m-distance" part of the question is just to throw you off, because one particular speed obviously stays constant over any distance. Hope that helps :)
Answer:
Any binary molecular compound of hydrogen and a Group 6A element above Selenium will be less acidic, so water and dihydrogen sulfide are less acidic in aqueous solution than hydrogen selenide.
Explanation:
Going down in a group increases the atomic radius and a greater atomic radius implyes greater ionic radius.
When ionization takes place in these compounds they yelds protons (hidrogen ion) and an lewis base (anion). The greater the ionic radius the greater its stability, thus the periodic tendency is increaing the acidity of binary hidrogen compounds when going down a group. On the other hand going up a group decreases acidity, so any molecular compound of hydrogen and a Group 6A element above Selenium will be less acidic, so water and dihydrogen sulfide are less acidic in aqueous solution than hydrogen selenide.