There are new ideas and questions that people are trying out and solving. Based off of that, the theories and ideas that we have now will change and evolve with the theories that have been tested and the questions that have been answered.
Yes, S-blocks are metals except for helium and hydrogen. The S-block metals are shiny, silvery and relatively soft, although they can easily lose electrons. Helium and hydrogen have valence electrons but also lack some similar properties as the other metals.
Answer:
sun, air, water, wind and ocean current
Explanation:
As sun is the major source of energy on earth, the earth gets heated due to solar energy, this creates convection currents in the Air and Water, the heating of these areas create wind and ocean currents due to difference in temperature and pressure.
Answer is: 4) The same subscripts are on each side of the equation.
For example, balanced chemical reaction:
2Mg + O₂ → 2MgO.
1) The same number of atoms is on each side of the equation: two magnesium atoms and two oxgen atoms.
2) The formulas for all substances are correct: in magnesium oxide (MgO), magnesium has oxidation number +2 and oxygen -2, so formula is good, because compound must be neutral.
3) The same mass is represented on each side of the equation: because there is same number of atoms, the mass is the same.
4) The same subscripts are on each side of the equation: oxygen does not have same subscripts.
