Answer: True.
Explanation.
The group 7A is actually named group 17.
That group is the halogens: F, Cl, Br, I, At, and Ts (Ts is one of the last elements discovered).
Those elements have 7 valence electrons (notice that it is the same number as the second digit in 17).
The atoms with 7 valence electrons will "easily" gain one electron to get the configuration of the next noble gas (8 valence electrons). That is why these elements gain electrons to form ions.
When atoms gain electrons form anions (negative ions). For example: F(-), Cl(-), Br(-), I(-).
The maximum temperature that a PVC can withstand is 130° C. Beyond this the PVC will melt. From the choices given the correct answer is option D. 130° C.
By definition, we have to:
A molecule is a group of at least two atoms in a defined configuration linked by chemical bonds.
We have two types of molecules:
1) several atoms of a single chemical element, as in the case of oxygen. (O2)
2) Atoms of different elements, as in the case of water. (H2O)
Answer:
the best description of a molecule is:
A: A molecule of an element is composed of at least two types of atoms.
The answer is b. propel should be guided by the way of nature
There are 70.90g of Cl2 in 1 mol (because 35.45g Cl in one mol). So 77.1g/70.9g≈1.0874 mol.
