Answer:
bromine is more reactive non-metal.
Explanation:
Both the elements have to gain 1 electron but the size of bromine is less than the size of astatine. And therefore, the tendency of accepting an electron by bromine is more than the tendency of astatine. Hence, bromine is more reactive non-metal.
The number of oxygen atoms that are in 4 Al₂O₃ are 12 atoms
<u><em> Explanation</em></u>
- The subscript in a chemical formula indicate the number of atoms of element immediately before the subscript.
- coefficient is the number in front of the formula and tells us how many molecules of a given formula are present.
- Since 4Al₂O₃ has coefficient of 4 and the subscript of O is 3 the number of O atoms = 4 x 3=12 atoms
Atoms are electrically neutral because the number of protons, which carry a 1+ charge, in the nucleus of an atom is equal to the number of electrons, which carry a 1- charge, in the atom. The result is that the total positive charge of the protons cancels out the total negative charge of the electrons so that the net charge of the atom is zero. Most atoms, however, can either gain or lose electrons; when they do so, the number of electrons becomes different from the number of protons in the nucleus. The resulting charged species is called an ion.
Atomic mass Ca = 40.078 a.m.u
40.078 g -------------------- 6.02x10²³ atoms
72.8 g ---------------------- ??
72.8 x ( 6.02x10²³) / 40.078 =
4.38x10²⁵ / 40.078 = 1.093x10²⁴ atoms
hope this helps!
Answer:
d. cells are made of atoms and molecules. :)
Explanation:
hope i helped
