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2 years ago

How can carbon dating be used to study the history of the earth?

1 answer:

7 0

The amount of carbon in fossils and artifacts decreases when the get older, so you can find out how old an object or fossil is by finding out how much carbon is in it.

You might be interested in

Is shaving cream a constant for making fake snow?<br><br> U get 71 pts!

Inessa [10]

Yes. It is made from baking soda and shaving cream but shaving cream is a constant. You could use things like corn flour instead of baking soda.

6 0

3 years ago

2. Which of the following elements does not lose an electron easily? (a) Na (6) F (c) Mg (d) Al

vaieri [72.5K]

Answer:

Answer: (b) F

Explanation:

Sodium has 1, magnesium has 2 and Aluminium has 3 electrons in its outermost shell whereas Fluorine has 7 electrons in its outermost shell hence Fluorine does not lose electrons easily.

The electronic configuration of fluorine is 2,7.

Fluorine is the ninth element with a total of 9 electrons.

The first two electrons will go in the 1s orbital.

The next 2 electrons for F go in the 2s orbital.

The remaining five electrons will go in the 2p orbital. Therefore the F electron configuration will be 1s22s22p5.

3 0

1 year ago

When the equation Sn + HNO₃ → SnO₂ + NO₂ + H₂O is balanced in acidic solution, what is the smallest whole-number coefficient for

balu736 [363]

Answer:

Explanation:

Hello,

In this case, for the given reaction we first assign the oxidation state for each species:

$Sn^0 + H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 + N^{4+}O^{2-}_2 + H^+_2O^-$

Whereas the half reactions are:

$Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O$

Next, we exchange the transferred electrons:

$1\times(Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-)\\\\4\times (H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O)\\\\\\Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\4H^++4H^+N^{5+}O^{-2}_3 +4e^-\rightarrow 4N^{4+}O^{2-}_2+4H_2O$

Afterwards, we add them to obtain:

$Sn^0+2H_2O+4H^++4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4H^++4N^{4+}O^{2-}_2+4H_2O$

By adding and subtracting common terms we obtain:

$Sn^0+4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4N^{4+}O^{2-}_2+2H_2O$

Finally, by removing the oxidation states we have:

$Sn + 4HNO_3 \rightarrow SnO_2 + 4NO_2 + 2H_2O$

Therefore, the smallest whole-number coefficient for Sn is 1.

Regards.

6 0

3 years ago

For lunch, a patient consumed 3 oz of skinless chicken, 3 oz of broccoli, 1 medium apple, and 1 cup of nonfat milk (see Table 3.

Volgvan

Lunch of a patient has 3 oz skinless chicken, 3 oz of broccoli, 1 medium apple, and 1 cup of nonfat milk

Energy content of 3 oz skinless chicken is = 110 kcal

Energy content of 3 oz broccoli = 30 kcal

Energy content of 1 medium apple = 60 kcal

Energy content of 1 cup non-fat milk = 90 kcal

So the kilocalories of energy patient obtained from lunch

= 110 kcal+ 30 kcal + 60 kcal + 90 kcal = 290 kcal

3 0

2 years ago

A weak acid, HF, is in solution with dissolved sodium fluoride, NaF. If HCl is added, which ion will react with the extra hydrog

kumpel [21]

Answer:

c. F1-

Explanation:

In this chemical reaction the expression is:

HF + NaF → NaHF2

The ion that always keep the negative charge is the fluorine with a -1, if in this mixture there is more positive ions (H1+) the negative ion (F1-) will join with them.

Remember that also the Cl1- will be free, but the fluorine is more reactive than the fluorine.

5 0

2 years ago