The Atomic Mass of a radium atom is approximately 226. It is a highly radioactive element found in group 2 of the Periodic Table.
The density of radium at about room temperature is 5.5  g·cm−3. That's 5.5 grams per cubic centimeter, or 5.5 grams per milliliter. A link to the Wikipedia article on radium is provided.
An average atom of radium has an atomic number of 88, which means it has 88 protons in its nucleus. It also typically contains 138 neutrons, resulting in its most stable isotope, radium-226. Radium is an alkaline earth metal and is known for its radioactive properties, emitting alpha particles and gamma rays as it decays. Additionally, it has an atomic mass of approximately 226 u (atomic mass units).
There are 88 protons in a radium atom.
The atomic mass of radium is approximately 226 atomic mass units.
Radium decays in any of (at least) four different ways, depending on isotope and, in some cases, on luck, as some isotopes can decay in different ways. The most important way radium can decay is by alpha emission. Nearly all naturally occurring radium decays this way, and so do the majority of synthetic isotopes. In this case, radium emits an alpha particle, which can be regarded as a helium nucleus, and the daughter atom is radon. The isotope of radon is depends on the isotope of radium involved; the mass number of the radon is always equal to the mass number of the radium minus four. Some heavier radium isotopes undergo negative beta decay, in which case the decay products are an actinium atom and a negative beta particle, which can be viewed as an electron. Some lighter radium isotopes undergo positive beta decay, in which case the decay products are a francium atom, a positive beta particle, which can be viewed as a positron, and an electron type antineutrino. A few radium isotopes also rarely undergo what is called cluster decay, and the most important naturally occurring isotope, radium-226 is among these. Cluster decay involves emission of a nucleus larger than an alpha particle, and in the case of radium all known cluster decays emit carbon-14 nuclei. In this case, the daughter atom is lead, with a mass number that is 14 lower than the mass number of the parent. So radium-226 can emit a carbon-14 nucleus, leaving a lead-212 atom.
The density of radium at about room temperature is 5.5  g·cm−3. That's 5.5 grams per cubic centimeter, or 5.5 grams per milliliter. A link to the Wikipedia article on radium is provided.
Hydrogen atom has 1 proton and 1 electron; radium has 88 protons and electrons. Also radium is radioactive.
There are 88 protons in a radium atom.
Radium is a chemical metal element. There are 88 electrons in a single atom.
The atomic mass of radium is approximately 226 atomic mass units.
The discoveries of radium and polonium doesn't affect the atom model.
The number of protons of an atom is given by its atomic number. Checking the periodic table, we see that the atom with 88 protons is radium. The isotope of radium with 138 neutrons would thus be 226Ra.
Radium decays in any of (at least) four different ways, depending on isotope and, in some cases, on luck, as some isotopes can decay in different ways. The most important way radium can decay is by alpha emission. Nearly all naturally occurring radium decays this way, and so do the majority of synthetic isotopes. In this case, radium emits an alpha particle, which can be regarded as a helium nucleus, and the daughter atom is radon. The isotope of radon is depends on the isotope of radium involved; the mass number of the radon is always equal to the mass number of the radium minus four. Some heavier radium isotopes undergo negative beta decay, in which case the decay products are an actinium atom and a negative beta particle, which can be viewed as an electron. Some lighter radium isotopes undergo positive beta decay, in which case the decay products are a francium atom, a positive beta particle, which can be viewed as a positron, and an electron type antineutrino. A few radium isotopes also rarely undergo what is called cluster decay, and the most important naturally occurring isotope, radium-226 is among these. Cluster decay involves emission of a nucleus larger than an alpha particle, and in the case of radium all known cluster decays emit carbon-14 nuclei. In this case, the daughter atom is lead, with a mass number that is 14 lower than the mass number of the parent. So radium-226 can emit a carbon-14 nucleus, leaving a lead-212 atom.
There is no such atom as Radium 87 - it is Radium 88 and thus has 88. Francium is 87.
The neutral radium atom has 88 electrons, the radium cation has 86 electrons.
Radium has 88 protons. The atomic mass of the most stable radium isotope - 226Ra - is 226,025 409 8(25).
The number of neutrons in the nucleus in any atom varies, however, the average is easy to find. The atomic number is the number of both protons and electrons. The atomic mass is the number of AMUs (atomic mass units) in the atom. 1 amu is the same as the mass of 1 proton or 1 neutron. the mass of the electrons is negligible. Because of this, subtract the atomic number from the atomic mass and you should have the average number of neutrons.