A. the wax is a both; 1. physical change-solid to liquid.
2. chemical change- burned to CO2 + H20 + heat + carbon as seen as black on the rod
b. the wick is neither; the wick does not change, just provides conduit for wax to flame
c. the glass rod is physical change; the carbon is only deported
HOPE THIS HELPS, IVE ALSO LEARNING BEEN LEARNING THIS RECENTLY
<span>Scientists have determined that the center of the earth is 6371 km below the surface. But how has this been determined? Many people might answer that question by saying scientists can drill into the Earth with machines. However, the drilling rigs that scientists use can only drill about 20 km in the Earth which is not very deep! In other words, we can only drill into upper part of the crust of the earth. Extremely high temperatures and pressures within the Earth make drilling into it very difficult</span>
Answer:
DO NOT TASTE IT, but all the rest are correct
Explanation:
Answer:
Combination reaction or synthesis reaction
Explanation:
Given reaction:
CO + H₂O → H₂CO₃
The type of reaction shown above is a combination or synthesis reaction. A combination reaction is one in which a single product is formed from two or more reactants.
In the given reaction carbon monoxide combines with water to produce hydrogen carbonate.
The formation of compounds from the union of their constituent elements falls into this category of reactions.
Answer:
Metallic bonding
Explanation:
Metals have low ionization energies. Therefore, their valence electrons are easily delocalized (attracted to the neighbouring metal atoms). These delocalized electrons are then not associated with a specific metal atom. Since the electrons are “free”, the metal atoms have become cations, and the electrons are free to move throughout the whole crystalline structure.
We say that a metal consists of an array of cations immersed in a sea of electrons
.
The electrons act as a “glue” holding the cations together.
Metallic bonds are the attractive forces between the metal cations and the sea of electrons.
In an NaK alloy, for example, the Na and K atoms contribute their valence electrons to the "sea". The atoms aren’t bonded to each other, but they are held in place by the metallic bonding.
