After 3 half life periods you would have 5 grams of krypton left because half of 40 is 20 half of 20 is 10 and half of 10 is 5
Answer:
B) They will react because X and Y can share two pairs of electrons to become stable
Explanation:
The electron configurations of two elements x and y are given :
X: 1s2 2s2 2p6
Y: 1s2 2s2 2p6 3s2 3p6
The statement that is true for both the elements is that, they both will react as they both can share two pairs of electrons to become stable.
To become stable the outermost shell or p orbital should have 8 electrons, so element X can gain 2 atoms to become stable.
Element Y can also react as it can also share two atoms to fulfill its 3p orbital and will stable.
Hence, the correct option is "B".
Answer:
HCO₂
Explanation:
From the information given:
The mass of the elements are:
Carbon C = 26.7 g; Hydrogen H = 2.24 g Oxygen O = 71.1 g
To determine the empirical formula;
First thing is to find the numbers of moles of each atom.
For Carbon:

For Hydrogen:

For Oxygen:

Now; we use the smallest no of moles to divide the respective moles from above.
For carbon:

For Hydrogen:

For Oxygen:

Thus, the empirical formula is HCO₂
It is very important<span> to know the shape of a molecule if one is to understand its reactions. It is also desirable to have a simple method to predict the geometries of compounds. For main group compounds, the </span>VSEPR<span> method is such a predictive tool and unsurpassed as a handy predictive method.</span>
Answer:
<em>Hello, Your answer will be </em><em>B) Jacob's backyard is on the north side of his house.</em>
<em>Hope That Helps!</em>