"if it is tested in a controlled setting with repeated results" is the statement among the choices given in the question that best describes that can possibly make this scientific claim valid. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer has helped you.<span>
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Answer: Option (E) is the correct answer.
Explanation:
When we move from top to bottom in a group then there occurs an increase in atomic size of the atoms due to increase in the number of electrons.
For example, in group 2A elements beryllium is the smallest in size whereas radium being at the bottom is the largest in size.
Also, atomic number of beryllium is 4 and atomic number of radium is 88.
Thus, we can conclude that out of the given options radium is the 2A element which has the largest atomic radius.
If we have a neutral atom, then it has the same number protons and neutrons.
The number protons and neutrons for neutral atom shows atomic number.
"A neutral atom has an atomic number of 20" means that atom has 20 protons (that give charge "+ 20" ) and 20 electrons (that give charge "-20").
Answer is 20 electrons.
Answer:
A mole (mol) is the amount of a substance that contains 6.02 × 10 23 representative particles of that substance. The mole is the SI unit for the amount of a substance. There are, therefore, 6.02 × 10 23 water molecules in a mole of water molecules. Water (H2O) is made from 2 atoms of hydrogen and 1 atom of oxygen.
