C is the correct answer. Double displacement reaction, also called as metathesis, is a type of reaction wherein two compounds react to form new compounds. This case the cations and the anions of the reactants replace each other forming the new compounds.
Answer:
OPTION (A) : Testing a rock sample for gold content
Explanation:
For testing a rock sample of gold content you will need a Chemist. To test the material, the sample is rubbed on black stone which will leave a mark on the stone. This mark is tested by applying aqua fortis i.e nitric acid on the mark. If the mark gets dissolve then the material is not gold. If the mark sustain the it is further tested by applying aqua regia i.e nitric acid and hydrochloric acid which will prove the sample is of gold if it gets dissolve on using hydrochloric acid. The purity of the sample can be checked by differing the concentration of the aqua regia and comparing it with the gold material of the known purity.
Answer:
Covalent bonding
Explanation:
In covalent bonding, the electrons are shared to fill the octet rule (8 electrons in valence shell). CCl4 tends to do covalent bonding because the the 4 valence electrons are Carbon are shared with the Chlorine atoms so that each chlorine atom has a full octet and chlorine shares its electrons to fill the octet of carbon.
Also, since carbon and chlorine are both non-metal, non-metal things exhibit covalent bonding thus this is covalent bonding as well. Ionic boding is for metal and non metal pair where electrons are transferrred, in our case, electrons are shared, they are not transferred.
Ruler is the answer of this question
Answer:
When an electron is hit by a photon of light, it absorbs the quanta of energy the photon was carrying and moves to a higher energy state. One way of thinking about this higher energy state is to imagine that the electron is now moving faster, (it has just been "hit" by a rapidly moving photon).
Explanation: pls mark brainliest :))
