The valence level of an atom refers to the number of electrons that reside in the upper most energy level. Nitrogen has an atomic number of 7 and therefore has 7 electrons. The first energy level (1) holds 2 electrons, leaving 5 electrons to reside in the second energy level (2s and 2p). Therefore the valence of nitrogen is 5.
As a Depressant, it acts like a depressant
The correct answer is 1000 Kg/M³
Density of water =1-g/cm3.
We know 1- g= 10^-³ Kg
cm³ =(10^-2)³= 10^-6
Substituting we get
Density of water
= 1 x (1x10^-³)/10^-6 Kg/M³
= 1x10^3 = 1000 Kg/M³
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what is density?</h3>
Density is the mass of a material substance per unit volume. Density is defined as d = M/V, where d represents density, M is mass, and V is volume. Density is generally measured in grammes per cubic centimetre. Water, for example, has a density of 1 gramme per cubic centimetre, but Earth has a density of 5.51 grammes per cubic centimetre. Density is sometimes measured in kilos per cubic metre (in metre-kilogram-second or SI units). The density of air, for example, is 1.2 kilogrammes per cubic metre. Textbooks and handbooks list the densities of common solids, liquids, and gases.
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2Na + 2H₂O ⇒ 2NaOH + H₂
n(Na):n(NaOH)=2:2, n(NaOH)=n(Na)=3mol
m(NaOH)=n·M= 3mol · 40g/mol(molar mass, 23+16+1)=120g.
The elements calcium, gold, iron and sodium are all metals. They all have a tendency to donate their valance electrons, rather than acquiring additional valance electrons. They all form metallic bonds, in the form of a shared electron cloud. They all have the electrical conductivity and metallic luster which comes with metallic bonds.