They do not change the nature of the substance unless a chemical change occurs along with the physical change. These may be irreversible, but the result is still composed of the same molecules. When you cut your hair, that is a physical change, even though you can't put the hair back on your head again
Calcium oxide + water = calcium hydroxide.
Magnesium + hydrochloric acid = magnesium chloride + hydrogen.
Sodium hydrogen carbonate + citric acid = Na3C6H5O7(aq)+3H2O(l)+3CO2(g)
Iron + salt water = 4Fe(OH)3 (rust)
Answer:
See below.
Step-by-step explanation:
The two isotopes are Cl-35 and Cl-37.
The average atomic mass (35.45 u) is closer to 35 u, so most of the atoms are Cl-35.
mass number = number of protons + number of neutrons
A = p + n
35 = 17 + n
n = 35 – 17
n = 18
∴ Most chlorine atoms contain 18 neutrons.
Correct answer: C) dispersion forces
Dispersion forces are the intermolecular forces of attraction present in all types of molecules. These are the weakest forces of attraction in which atoms of the molecule align in such a way that weak forces of attraction develop between electron cloud of one atom and the positively charged nucleus of the adjacent atom. This is referred to as induced dipole-induced dipole type of interaction. Therefore in dispersion forces temporary dipoles are developed due to constant motion of electrons that results in asymmetric electron distribution around the nucleus in an atom.
Answer:
fertilization i think
Explanation:
because during fertilization process two identicle cell divisions takes place