Hey there!
A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.
If 50%, or half, of the element remains after 4000 years, that means the half life must be 4000 years.
Hope this helps!
The heat required to raise the temperature of a certain mass of sample to a specific temperature change, we use the formula mCpΔT where m is mass, Cp is the specific heat of the substance and ΔT is the temperature change. In this case, we substitute and form 1.25 g x 0.057 cal/g C *20 C equal to 1.425 calories.
The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust,[2] or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean first experienced a rise in oxygen, approximately 2.4 billion years ago (2.4 Ga) to 2.1–2.0 Ga during the Paleoproterozoic era.[3] Geological, isotopic, and chemical evidence suggests that biologically produced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere,[4] causing many existing species on Earth to die out.[5] The cyanobacteria producing the oxygen caused the event which enabled the subsequent development of multicellular forms.
Explanation:
The given data is as follows.
= 1.5 atm, 
= 20 L, 
= (28 + 273) K = 301 K
= 5 atm, 
= ?, 
= (50 + 273) K = 323 K
Formula to calculate the volume will be as follows.
= 
Putting the given values into the above formula as follows.
=
= 
= 0.64 L
Thus, we can conclude that the change in volume of the balloon will be 0.64 L.
Answer:
A) increasing dispersion interactions
Explanation:
Polarizability allows gases containing atoms or nonpolar molecules (for example, to condense. In these gases, the most important kind of interaction produces <em>dispersion forces</em>, <em>attractive forces that arise as a result of temporary dipoles induced in atoms or molecules.</em>
<em>Dispersion forces</em>, which are also called <em>London forces</em>, usually <u>increase with molar mass because molecules with larger molar mass tend to have more electrons</u>, and <u>dispersion forces increase in strength with the number of electrons</u>. Furthermore, larger molar mass often means a bigger atom whose electron distribution is more easily disturbed because the outer electrons are less tightly held by the nuclei.
Because the noble gases are all nonpolar molecules, <u>the only attractive intermolecular forces present are the dispersion forces</u>.
