Calcium with water:
When a metal reacts with water( cold water or hot water) then the products formed are metal hydroxide and hydrogen gas.
Metal + steam --------> Metal hydroxide + Hydrogen
Calcium reacts with cold water to form calcium hydroxide and hydrogen gas:
potassium with water.
Potassium reacts violently with cold water to form potassium hydroxide and hydrogen gas:
2K(s)+ 2H2O(l) --------> 2KOH(aq) + H2(g) + heat.
In this reaction so much heat is produced get hydrogen gas formed catches fire and burns explosively.
Answer:
It could probably be O.
Explanation:
Just like eye or hair color, our blood type is inherited from our parents. Each biological parent donates one of two ABO genes to their child. The A and B genes are dominant and the O gene is recessive. For example, if an O gene is paired with an A gene, the blood type will be A.
Density is the ratio of the substance's mass to volume. To know the effects of temperature on the density of the liquid, we must look at the mass and volume dependence. Mass is always constant, so it is not affected by temperature. For volume, generally, the molecules of the liquid occupy a greater space when heated because of the rapid collisions of the liquid molecules. Thus, as temperature increases, the volume of liquid also increases, although slightly only. That means that density would decrease.
Answer:
a) As I remember "the atomic spectra" of bohr
1- Existence of a positively charged nuclei in the centre of the atom
2- Number of negatively charged electrons = number of positive charges ported by the atom.
3- Electrons navigate in fixed energy levels , with a high speed without gain or loose energy
4- centrifugal force is in equilibrium with attraction force.
5- The empty space between energy levels is forbidden for electrons.
Answer:
Because in elastic collisions there is no heat emission or absorption.
Explanation:
A collision is considered elastic when the total kinetic energy of the study system is conserved during the collision. Since the total kinetic energy is conserved, heat is not emitted or absorbed during the collision. Since the emission or absorption of heat is what produces changes in temperature, If the system remains at a constant temperature, there were only elastic collisions.