the first step would be gathering information , and making sure its correct
The answer would be A.
Combination reaction, otherwise known as synthesis reaction, occurs when two or more substances react and form a single, more complex substance.
A combination reaction looks like this in an equation:
<em> A + B </em><em>→ </em><em>AB</em>
reactants product
So from two reactants they become one product.
Let's take a look at choice A.
2H₂O(l) → 2H₂(g) + O₂(g)
reactant product(s)
Notice that from one substance, it broke down into two substances. So this is not a combination reaction. This is what you call a <em>decomposition reaction. </em>
Answer:
Force, 
Explanation:
It is given that,
Length of the room, l = 4 m
breadth of the room, b = 5 m
Height of the room, h = 3 m
Atmospheric pressure, 
We know that the force acting per unit area is called pressure exerted. Its formula is given by :
So, the total force on the floor due to the air above the surface is 
. Hence, this is the required solution.
Answer:
If two or more atoms of the same element combine, they produce a molecule, for example, H2, O2, O3, etc.
If, however, two (or more) atoms of different elements combine, they produce a compound, for example, NO, CO, FeS, NaCl, etc. The compound may be called a molecule if it is made of independent units, such as NO and CO. However, FeS and NaCl are not molecules because there is no independent unit made of one atom of Fe and a single atom of sulfur or a single unit of Na and Cl. These compound are made of a network of large number of ions of Fe^+2 and S^-2 and Na^+1 and Cl^-1 as a ionic crystallines. If you could isolate a single FeS or NaCl (for example in the gaseous state) you could call them also molecules.
Explanation:
