Explanation:
atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption. The electron absorbs the energy and jumps to a higher energy level. In the reverse process, emission, the electron returns to the ground state by releasing the extra energy it absorbed
Answer:
The weights of all elements are always compared to the Carbon-12.
Explanation:
The weights of all elements are always compared to the Carbon-12 because the mass of carbon is 12 which is the exactly the sum of protons and neutrons.
Oxygen was also considered the standard for some time but later this stander was rejected because in natural O¹⁷ and O¹⁸ were also present and this create the two different atomic mass tables.
AMU:
Atomic mass unit is define as the 1/12 the mass of an atom of carbon-12.
C12 has six neutron and six protons in the nucleus.
This unit is used to express the masses of atoms. We know that masses of atoms are very small and we do not have any such type of balance that can measure very small quantity. So that is way we use this scale to measure small quantity. For example, according to this scale
relative atomic mass of hydrogen is 1.008 amu
relative atomic mass of oxygen is 15.999 amu
relative atomic mass of uranium is 238.0289 amu
relative atomic mass of chlorine is 35.453 amu
Answer:
C, B ,A(in the order of the blanks)
Explanation:
A centrifuge uses centrifugal force to seperate 2 substances with different densities, the lighter one at the top. This cannot be done with homogeneous mixtures
When compounds form, the atoms that bonded get a stable arrangement of electrons.
Compounds form because their atoms get a more stable arrangement than they had in the reactants.
A stable arrangement is a <em>complete octet</em> of eight electrons in the valence shell
.
Answer:first one: 3.0g second one: 10g H2O(I)
Explanation: