The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
Answer: Sodium bromide is an ionically bonded compound.
(NaBr: Sodium Bromide)
Answer: Physical change : tearing of paper, fixing of wtaer
Chemical change: rusting of iron , electrolysis of water, Rancidification
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance.
Example: tearing of paper, fixing of wtaer
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state.
Example: rusting of iron , electrolysis of water, Rancidification
Answer: O fluorine to complete the octet rule
that right
Answer:
1 ) H2O 2) Hydrogen and oxygen 3) Compound
Explanation:
1) To write a chemical formula, you write the number of molecules of an element (2 hydrogen atoms + 1 Oxygen atom, or H2O). The letters represent the element's notation on the periodic table, while the number that follows it represents the number of atoms of that particular element within the compound. If there is no number that follows the letter, there is only one.
2) Letter "H" on the periodic table represents hydrogen, while "O" represents oxygen
3) You can tell that this is a compound because it is made of two or more elements found on the periodic table