Using the ideal gas equation:
PV = nRT
Substituting n with mass / Mr
PV = mRT/Mr
Density = m/V
So rearranging:
Density = PMr/RT
P = 1 atm
R = 0.082 L atm / K mol
T = 273 K
Density = (1 x 80.6) / (0.082 x 273)
Density = 3.6 g / L
Neutrons actually don't carry an electrical charge, which is why they are called neutrons because they are "Neutral".
Answer:
The false statement is :
- Pyrite is an ore of gold and is used in jewelry making.
- Cobalt is not used in medicine.
Explanation:
Pyrite is an ore of iron sulfide found on the Earth and in coal, limestone and in many deposits of metallic ores. Due to its luster and pale yellowish color it appears as gold due to which it is also termed as Fool's gold.
It is used in firearms , in production of sulfur dioxide gas, etc.
Cobalt is used as medicine to treat cancer patient. Co-60 is used in treatment of cancer in which gamma rays produced by Co-60 are used to kill tumor cells in a cancer patient.
Where as talc is used in industries like : paper making, food, paints, plastics etc. Quartz is primary material used to prepare glass and cobalt is used as
Which of these is an isoelectronic series? 1) na+, k+, rb+, cs+ 2) k+, ca2+, or, s2– 3) na+, mg2+, s2–, cl– 4) li, be, b, c 5) n
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An isoelectronic series is where all of the ions listed have the same number of electrons in their atoms. When an atom has net charge of zero or neutral, it has equal number of protons and electrons. Hence, it means that the atomic number = no. of protons = no. of electrons. If these atoms become ions, they gain a net charge of + or -. Positive ions are cations. This means that they readily GIVE UP electrons, whereas negative ions (anions) readily ACCEPT electrons. So, to know which of these are isoelectronic, let's establish first the number of electron in a neutral atom from the periodic table:
Na=11; K=19; Rb=37; Cs = 55; Ca=20; S=16; Mg=12; Li=3; Be=4; B=5; C=6
A. Na⁺: 11-1 = 10 electrons
K⁺: 19 - 1 = 18 electrons
Rb⁺: 37-1 = 36 electrons
B. K⁺: 19 - 1 = 18 electrons
Ca²⁺: 20 - 2 = 18 electrons
S²⁻: 16 +2 = 18 electrons
C. Na⁺: 11-1 = 10 electrons
Mg²⁺: 12 - 2 = 10 electrons
S²⁻: 16 +2 = 18 electrons
D. Li=3 electrons
Be=4 electrons
B=5 electrons
C=6 electrons
The answer is letter B.
Energy of reactants is higher than the products , I am not sure through
