18.The octet rule tells us that in every chemical
reactions, elements will either gain or lose electrons to attain the noble gas electron
configuration. This stable<span> electron configuration is known as the octet configuration
since it is composed of 8 valence. Oxygen’s electron configuration is 1s2 2s2
2p4. So when</span> oxygen reacts with
other elements to form compounds, it completes the octet configuration by
taking 2 electrons from the element
it reacts with
19. Actually pure metals are made up not of
metal atoms but rather of closely packed cations (positively charge particles).
These cations are then surrounded by a pack of mobile valence electrons which
drift from one part of the metal<span> to
another. This is called metallic bond.</span>
20. This is the
energy which is needed to break a single bond. When the dissociation energy is
large, this means that the compound is more stable. Since carbon to carbon
bonds have high dissociation energy, therefore they are not very reactive.
21. Network solids are type of solids
in which the atoms are covalently bonded to one another, so they are very
stable. It takes higher temperature to melt them because breaking these
covalent bonds required greater energy. Some examples are:
- Diamond
<span>-Silicon Carbide</span>
Answer:
d water I believe I'm sorry if it's wrot
Answer:
1. See explanation below
2. Density
3. Masses
Explanation:
1. Your picture is a bit too small to see the values but maybe this will help you.
To determine the maximum maximum mass in grams that triple beam balance can measure all you have to do is add up the maximum of each beam. So all you need to do is see the value at the last notch of each beam.
However, if you are referring to the picture that is attached in the bottom: The answer would be 610g. Because the last notches of each beam are as follows:
100 g
500 g
10 g
So we add that we get 610g.
2. density can be computed using the formula:
D = M/V
where:
D = density
M = mass
V = volume
As you can see in the both figures A and B measure 20 g, this means that their masses are the same. The density of objects can be different when either their masses, or their volumes are different. So even if they have the same mass, they can have different densities because they have different volumes.
3. Force of gravitational attraction between two objects is dependent on the masses of the two objects and the distance. The larger the mass, the stronger the gravitational force of attraction. This means that they have a direct relationship. Now when it comes to distance, the further apart they are the weaker the gravitational force of attraction, or in other words, they are indirectly related.
Answer:
A
Explanation:
B and D have to do with plants
and C has nothing to do with cellular resporation.