Answer: 68.
Explanation:
The atomic number is the number that idenfities an element.
The atomic number is the number of protons of an element.
Every element has a different number of protons.
The elements are arranged in the periodic table as per their atomic number (number of protons).
The first element is hydrogen (H), its atomic number is 1, and it has 1 proton.
The second element is helium (He), its atomic number is 2 (it has 2 protons)-
Those two elements form the first period (row) of the periodic table.
The second row (period) has the elements Li, Be, B, C, N, O, F and Ne, whose respective atomic numbers (number of protons are) 3, 4, 5, 6, 7, 8, 9, and 10, respectively.
And so, you may idenfity each of the 118 elements known, with a different atomic number (number of protons).
Answer:
The moon is only visible during part of each month. ... When the moon is opposite the sun in the sky (which is when full moon happens), it will rise as the sun sets and set as the sun rises. Therefore, a full moon will be up all night long, but not during the day.
Explanation:
Answer:- 
Explanations:- The first reaction is combustion reaction as the hydrocarbon is burned in presence of oxygen to give carbon dioxide and water.
Second reaction is the synthesis reaction as in general a synthesis reaction looks like:
Third reaction is the decomposition reaction as it looks opposite of synthesis reaction.
In general, a single displacement reaction looks like:
Fourth reaction is single replacement reaction as bromine is replaced by chlorine.
So, the correct choice is the last reaction, .
Trees and forest play an important role in balancing the amount of Carbon in the atmosphere through the process of photosynthesis where plants make their own food with carbon dioxide, using energy from the sunlight. Therefore, deforestation (cutting down of trees) has an effect on the carbon cycle also the greenhouse gas effect and global warming. Deforestation reduces the removal component of this cycle, thus, increasing the carbon dioxide in the air.
Answer:
Gibbs equation helps us to predict the spontaneity of reaction on the basis of enthalpy and entropy values directly. When the reaction is exothermic, enthalpy of the system is negative making Gibbs free energy negative. Hence, we can say that all exothermic reactions are spontaneous.
