1. Ca → Element
2. Proton → positive
3. H2O → compound
4. Fission → nuclear decay
5. Fusion → Nuclear synthesis
6. η → Neutron
7. e → electron
8. Atomic number → no of protons in nucleus.
Explanation
1. Ca (Calcium):
Calcium is an element with the atomic number of 20. It is an alkaline earth metal. The 99% of calcium is found in our bodies, in bones, teeth.
2. Proton:
Proton is a subatomic particle and it holds the positive charge. Proton is present in the nucleus of the atom.
3. H2O (water):
Water is a chemical compound and it's chemical formula is H2O. It's called compound as it contains 2 hydrogen and 1 oxygen atoms bonded together through the covalent bond.
4. Fission:
Fission is a process in which large massive unstable nucleus splits into the smaller, less heavier and stable nuclei. The energy is re;eased in the form of radiations during this process. It's called as the radioactive decay.
5. Fusion:
Fusion is opposite of the fission reaction. As in this case the two nuclei combines to form a single large nucleus. That's why it is a nuclear synthesis process.
6. η neutron:
Neutron is a subatomic particle and it is a neutral particle which is located inside the nucleus. n is a symbol used for the neutron.
7. e Electron:
The symbol for electron is e. It's a subatomic particle with negative charge. It is found in the orbits around the nucleus.
8. Atomic Number:
Atomic number is defined as the number of protons in the nucleus of an atom. IT is represented by Z.
That would be a nebula, which is an interstellar cloud of hydrogen gas, dust, and plasma. It is the first stage of a star's cycle.
Answer:
4.29 millimeters
Explanation:
Bats emit ultrasound waves: in air, ultrasound waves travel at a speed of

The frequency of the waves emitted by this bat is:

Therefore we can find the wavelength of the wave emitted by the bat by using the relationship between speed, frequency and wavelength:

Answer:

Explanation:
-The chemical formula for Molybdenum (V) Dichromate is 
-There are 21 moles of oxygen per one mole of Molybdenum (V) Dichromate
-We apply Avogadro's constant to find the number of atoms of oxygen:

Hence, there are
The work-energy theorem states that the net work done by the forces on an object equals the change in its kinetic energy.