Answer:
Metallic bonding is found in metals and their alloys. When the atoms give up their valence electrons, they form ions. These ions are held together by the electron cloud surrounding them. Metals are shiny because they have a lot of free (i.e. delocalized) electrons that form a cloud of highly mobile negatively charged electrons on and beneath the smooth metal surface in the ideal case. ... In the absence of any external EM field, the charges in the plasma are uniformly distributed within the metal.
Explanation:
In metallic bonding, the electrons are “surrendered” to a common pool and become shared by all the atoms in the solid metal.
Answer:
C
Explanation:
A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.
A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.
<span> A homogeneous mixture is composed of a single visible phase while a heterogeneous mixture has two or more</span>
Given:
Iron, 125 grams
T
1 = 23.5 degrees Celsius, T2 =
78 degrees Celsius.
Required:
Heat produced in kilojoules
Solution:
The molar mass of iron is 55.8
grams per mole. SO we need to change the given mass of iron into moles.
Number of moles of iron = 125 g/(55.8
g/mol) = 2.24 moles
<span>
Q (heat) = nRT = nR(T2 = T1)</span>
Q (heat) = 2.24 moles (8.314
Joules per mol degrees Celsius) (78.0 degrees Celsius – 23.5 degrees Celsius)
<u>Q (heat) = 1014.97 Joules or
1.015 kilojoules</u>
<span>This is the amount of heat
produced in warming 125 g f iron.</span>
The central vacuole stores materials, wastes, and helps give the plant structure and support.
Hope this helps!
