Answer:
Un elemento es un material compuesto de un simple tipo de átomo, un compuesto es una sustancia formada por dos o más elementos que se combinan químicamente y una mezcla es la combinación de sustancias, iguales o no, que pueden ser separadas por métodos físicos.
<em>espero que esto ayude :)</em>
Answer:
Its D Kr and Xe
Explanation:
Element from the same group have simmilar properties
If you now the atomic number ،its so easy to know how much electrons they have in outermost shell.
Friction is caused by two solids rubbing together quickly.
Answer: Gravitational forces are action-at-a-distance forces
Explanation:
Gravitational forces are action-at-a-distance forces that act between two objects even when they are held some distance apart. For example If you watch a roller coaster car move along its course, then you are witnessing an action-at-a-distance.