Answer:
Cement is a combination of calcium, silicone, aluminum, iron and lots of other ingredients to make side walks, home made crafts, etc. The person who invented concrete is Joseph Aspdin.
Explanation:
Answer:
The lanthanides and actinides together are sometimes called the inner transition elements.
Explanation:
They are called this because they come up in the periodic table after actinium
Hope this helps :)
Your answer is B because elements within the same column have equal numbers of valence electrons which determines the reactivity of an element.
