Explanation:
Metals and non-metals can be identified either by their position in the periodic table or by their properties.
he metal elements are found on the left hand side of the periodic table, and the non-metal elements are found on the right. You can imagine a zig-zag line, starting at B-Al-Si, separating metals from non-metals.
Explanation:
chemical compound, any substance composed of identical molecules consisting of atoms of two or more chemical elements. All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds
Answer:
1 Joule=0.2390057361 Calorie
789kj=789×0.2390057361×1000
=188575.5257829calorie
Explanation:
Hope u have understand
Answer:
1.26*10²³ particles are present in 12.47 grams of NaCl
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023 * 10²³ particles per mole. The Avogadro number applies to any substance.
So, first of all you must know the amount of moles that represent 12.47 grams of NaCl. For that it is necessary to know the molar mass.
You know:
- Na: 23 g/mole
- Cl: 35.45 g/mole
So the molar mass of NaCl is: 23 g/mole + 35.45 g/mole= 58.45 g/mole
Now you apply a rule of three as follows: if 58.45 grams are present in 1 mole of NaCl, 12.47 grams in how many moles will they be?

moles= 0.21
You apply a rule of three again, knowing Avogadro's number: if in 1 mole of NaCl there are 6,023 * 10²³ particles, in 0.21 moles how many particles are there?

number of particles= 1.26*10²³
<u><em>1.26*10²³ particles are present in 12.47 grams of NaCl</em></u>
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