D) burning magnesium ribbon, as combustion is a chemical reaction so causes chemical change. The other 3 options do not involve reactions so there isn't a chemical change.
Answer;
A scalene
Explanation;
A triangle is a geometric figure with three sides and three angles that always add up to 180 degrees.
Based on properties triangles can be classified as equilateral, scalene, isosceles and right triangles.
Equilateral triangles has all the three sides and the angles equal, an isosceles triangle has two of its sides equal, and two angles that are known as the base angles equal. A scalene triangle has all the three angles and sides different from each other. A right triangle is a triangle in which one of the angle is right angle or is 90 degrees.
An isosceles triangle may be a right triangle, equilateral triangle, and also may be an acute triangle, however an isosceles triangle can never be a scalene triangle
There are two types of rocks that make up the continental crust "sedimentary and metamorphic rocks." Sedimentary rocks are formed with pressure and compaction, and metamorphic rocks are made with heat and pressure. The earth's crust itself is made up of sedimentary rocks because they are mainly found a little under earths crust same goes with metamorphic rocks.
Hope this helps!
Explanation:
2. 
First, we need to find the number of moles of 
at 300K and 1.5 atm using the ideal gas law:
Now use the molar ratios to find the number of moles of ethane to produce this much .
Finally, convert this amount to grams using its molar mass:
3. 
Convert 75 g Zn into moles:
Then use the molar ratios to find the amount of H2 produced.
Now use the ideal gas law 
to find the volume of H2 produced at 23°C and 4 atm:
