Answer:
See below!
Explanation:
For the chemical formula, you need to have enough of each atom so that the charge is zero.
Aluminum has a +3 charge, and fluorine has a -1 charge. Since the charge has to be zero, you need three fluorines, giving you AlF₃.
Barium has a +2 charge, and oxygen has a -2 charge. Since the charges are equal in magnitude but opposite in sign, you only need one of each atom giving you BaO.
The name of the ionic compound will be the metal and then the nonmetal. When putting the nonmetal in, change the ending to "-ide". For example "chlorine" would be "chloride.
CaCl₂ ==> calcium chloride
Ga₂S₃ ==> gallium sulfide
K₃N ==> potassium nitride
AlF₃ ==> aluminum fluoride
BaO ==> barium oxide
It would take 147 hours for 320 g of the sample to decay to 2.5 grams from the information provided.
Radioactivity refers to the decay of a nucleus leading to the spontaneous emission of radiation. The half life of a radioactive nucleus refers to the time required for the nucleus to decay to half of its initial amount.
Looking at the table, we can see that the initial mass of radioactive material present is 186 grams, within 21 hours, the radioactive substance decayed to half of its initial mass (93 g). Hence, the half life is 21 hours.
Using the formula;
k = 0.693/t1/2
k = 0.693/21 hours = 0.033 hr-1
Using;
N=Noe^-kt
N = mass of radioactive sample at time t
No = mass of radioactive sample initially present
k = decay constant
t = time taken
Substituting values;
2.5/320= e^- 0.033 t
0.0078 = e^- 0.033 t
ln (0.0078) = 0.033 t
t = ln (0.0078)/-0.033
t = 147 hours
Learn more: brainly.com/question/6111443
Answer:
A.
Explanation:
hope this helped sorry if its wrong!
Answer:
Fluoride is commonly used in dentistry to strengthen enamel, which is the outer layer of your teeth. Fluoride helps to prevent cavities. It’s also added in small amounts to public water supplies in the United States and in many other countries. This process is called water fluoridation.
Explanation:
