Answer:
Explanation:
The probability of finding at least on pair is equal to 1 minus the probability of finding no pair. If x represents the number of pairs obtained in a game we have that:
Now lets consider the a game in which no pairs are obtained. The first card can be any, so we have 12 out 12 cards. The second card can't be the one matching the first card, so we have 10 out of 11. Similarly for the 3rd and 4th cards, we obtain:
This results in
Answer:
Number 4 is an example of a chemical reaction
Explanation:
heThe chalk is reacting with the vingear which is creating a new substance. The new substance is the gas that the reaction gives off.
Answer:
Explanation:
The electronic configuration of a lithium atom is 2.1 and that of a fluorine atom is 2.7
an atom of lithium donates an electron to an atom of fluorine to form an ionic compound. The transfer of the electron gives the lithium ion a net charge of +1, and the fluorine ion a net charge of -1.
Answer:
Explanation:
Hello there!
In this case, according to the attached solubility chart, it is possible for us to realize that about 88 grams of KNO3 are soluble at 50 °C but just 30 grams are soluble at 20 °C in the same 100 g of water.
In such a way, the crystalized mass of this solute can be calculated by subtracting the mass at 50 °C and the mass at 20 °C:
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