Answer:
Density = mass / volume.
If this is an ideal gas then 1mol will take up 22.4L of volume (fact about ideal gases you should remember)
Since you have 1mol then you know the volume of the gas that you have (22.4L)
Now, just convert 1mol of CO to grams.The ptable tells you that the mass of 1 mol of C is 12g and the mass of 1 mol of O is 16g. So the mass of 1 mol of CO is......... :):)
Now you have the mass and the volume, so just divide :) enjoy
The atomic number of an element tells you the number of protons within said element.
Scientists use carbon-14 to date ancient fossils.
Plants and animals absorb carbon-14 produced by cosmic rays. The ratio of C-14 to C-12 is constant when they are alive.
When they die, the C-14 decays to C-12, and the ratio changes.
Carbon-14 has a half-life of 5730 years. Thus, the object loses half its C-14 every 5730 years.
Scientists can use the C-14 to C-12 ratio to date fossils up to 70 000 years old.
The set that represent a pair of isotope is 9B AND 11B.
Isotopes are chemical element which have two or more forms, these forms have the same number of electrons but different number of neutrons.
In an atom of an element, the nucleus contains the neutron and the proton. For a neutral atom, the number of proton and neutron are always the same, while the number of neutron differ. Thus, for the correct option, B stands for the element Boron, which has atomic number of 5. This means that 9B has 5 electrons, 5 protons and 4 neutrons. For 11B, the isotope has 5 protons, 5 electrons and 6 neutrons. 9 and 11 are the mass number of the isotopes; mass number is the summation of number of proton and neutron.