There is no chemical change
2.43*1000.
There are 1000 grams in a kilogram
Answer:-
Alpha decay
Explanation:-
Uranium 238 has atomic number 92 and mass number 238.
Thorium 234 has atomic number 90 and mass number 234.
So, the change in atomic number as uranium 238 disintegrates into thorium234 = 92 – 90 = 2
So, the change in mass number as uranium 238 disintegrates into thorium234= 238 – 234 = 4
We know that when an alpha particle is emitted, the mass number decreases by 4 and the atomic number decreases by 2.
So when an atom of uranium 238 undergoes radioactive decay to form an atom of thorium-234, alpha decay has occurred.
Answer:
C. involve the attraction of opposite charges
Explanation:
<em>Ionic bonding</em> involves the attraction between <em>oppositely charged ions</em>, as in Na⁺ Cl⁻.
<em>Covalent bonding</em> involves the attraction between <em>negatively charged electrons and positivey charged nuclei</em>, as in a C-H bond.
A is <em>wrong</em>. Ionic bonding involves the transfer of electrons.
B is <em>wrong</em>. Covalent bonding involves the sharing of electrons.
D is <em>wrong</em>. Ionic bonds are usually stronger than covalent bonds.
Answer: Exocytosis is the reverse of endocytosis. Quantities of material are expelled from the cell without ever passing through the membrane as individual molecules. By using the processes of endocytosis and exocytosis, some specialized types of cells move large amounts of bulk material into and out of themselves.
Explanation:
