Answer:
- First: element.
- Second: Compound.
- Third: element.
- Fourth: Compound.
Explanation:
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In this case, since elements are composed the same atom and compounds are composed by two different atoms, we can see that:
- First: it is an element as each sphere seems to be the same.
- Second: It is a compound as two different type of spheres are shown, white and black, considering each sphere is a different element.
- Third: it is an element because the spheres are equal, in fact, it is a diatomic element as two atoms are joined per molecule.
- Fourth: It is a compound as well since each molecule has two colored spheres and one white sphere, meaning that it has two different atoms per molecule.
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H-1 only has 1 proton and 1 electron, so its mass number is 1.
H-2 has one more neutron so its mass number is 2
H-3 has one more neutron than H-2 so its mass number will be 3.
average atomic mass = 1 x 99% + 2 x 0.8% + 3 x 0.2%
=1.012
Answer:
You can divide the mass by the volume to calculate the density of the metal
Explanation:
Answer:
Noble gases are the least reactive of all elements
Explanation:
because they have eight valence electrons, which fill their outer energy level
Answer:
HCO3− + OH− ⇌ CO32− + H2O
hope it helps!!!!
