Helium - 4 isotope has 2 protons and 2 neutrons.
Its atomic number is 2 (the number of protons). Atomic number is the number of protons in the atom of an element and it identifies the element. All the isotopes of an element have the same atomic number (same number of protons). So, all the isotopes of hellium have 2 protons.
The number 4 that identifies the helium - 4 isotope is the mass number, i.e. the number of protons plus the number of neutron. So, helium-4 isotope has 2 protons and 2 neutrons. While, other isotopes of helium have 2 protons but different number of neutrons.
The atomic number enable us to deduce the number of electrons in an atom because the atoms are neutral, which implies that the positive and negative charge are equal. Given that the magnitude of the charge of electons and protons are equal but the sign is opposed (protons are positve and electrons are negative) the number of electrons in the atom equals the number of protonts. That is why the atomic number is also the number of electrons of the atom.
IT will be Refraction of light
830 mL. A 2.3 mol/L solution of CaCl2 has a volume of 830 mL
I am guessing that the concentration of your solution is 2.3 mol/L.
a) Moles of CaCl2
MM of CaCl2 = 110.98 g/mol
Moles of CaCl2 = 212 g CaCl2 x (1 mol CaCl2/110.98 g CaCl2)
= 1.910 mol CaCl2
b) Volume of solution
V = 1.910 mol CaCl2 x (1 L solution/2.3 mol CaCl2) = 0.83 L solution
= 830 mL solution
Igneous rock that forms from magma that cools slowly within Earth’s crust is likely to have larger crystals and a coarse-grained texture.
Igneous rock that forms from lava that cools quickly on Earth’s surface is known as extrusive igneous rock. Another word for extrusive is volcanic.
Because the sample of igneous rock formed on Earth’s surface, it is extrusive. Because it’s composed of mostly light-colored minerals, it is likely felsic.
Because the sample of igneous rock formed within Earth’s crust, it is intrusive. Because it contains a very high concentration of dark-colored, high-density minerals, it is likely ultramafic.
The fact that gabbro is an igneous rock suggests that it was formed from the cooling and crystallization of magma. The fact that it is intrusive means that it formed within Earth’s crust. The fact that it’s mafic suggests that it contains a high concentration of dark-colored, high-density minerals.
A. Two electrodes separated by an electrolyte that can generate an electrical current.
