Answer:
As you move across a period the electrons are being added to the same shell. But, protons are being added as well. This makes the nucleus more positively charged and, increasing protons has a greater effect than electrons. So, there is a greater nuclear attraction and, because the electrons are being added to the same shell that shell gets pulled in more. This causes a decrease in atomic radius.
Explanation:
Answer:
167.980.
Explanation:
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In this case, since additions involving the display of the result with the appropriate number of significant figures involve the solution of the system without looking at them:
Considering that 156.325 is significant to the thousandths and 11.65498 to the hundred thousandths, we infer that the result should be taken to the thousandths as well as 156.325; thus, we obtain:
Because the second decimal nine is rounded to ten and therefore the 7 is taken to 8.
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Answer:
3.01 × 10²³ molecules
Explanation:
Step 1: Given data
Moles of water (n): 0.500 mol
Step 2: Calculate the molecules of water present in 0.500 moles of water
In order to perform this calculation, we will use the Avogadro's number: in 1 mole of water there are 6.02 × 10²³ molecules of water.
0.500 mol × (6.02 × 10²³ molecules/1 mol) = 3.01 × 10²³ molecules
The outer electrons of an element are called the valence electrons. They help make an element stable.
Cesium : 1 valence electron<span>.
Magnesium : 2 valence electrons</span>
Radioisotopes are widely used to diagnose disease and as effective treatment tools. For diagnosis, the isotope is administered and then located in the body using a scanner of some sort.
