Answer:
Es la tercera por qué cuando el material varía va cambiando de estado
Explanation:
Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
Answer:
english:
Solid is the state in which matter maintains a certain volume and shape; liquid is the state in which matter conforms to the shape of its container, but varies only slightly in volume; gas is the state in which matter expands to fill the volume and shape of its container.
español:
Sólido es el estado en el que la materia mantiene cierto volumen y forma; el líquido es el estado en el que la materia se adapta a la forma de su recipiente, pero varía sólo ligeramente en volumen; el gas es el estado en el que la materia se expande para ocupar el volumen y la forma de su recipiente.
Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
The ratio of mole number of the reactants and products is equal to the coefficients. So the answer is a. 18.75 mol. b. 35.1 g. c. 1.38 * 10^5 g.
