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DENIUS [597]
3 years ago
8

According to early chemists, which substances were classified as elements?

Chemistry
1 answer:
ladessa [460]3 years ago
6 0
The best answer to your question would be B:those who could not be broken down by physical means.
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The solubility product for an insoluble salt with the formula M2X3 is written as ________, where s is the molar solubility
masha68 [24]

Answer:

36s^5

Explanation:

We have;

M2X3 (s)------> 2M^3+(aq)  + 3X^2-(aq)

If [M^3+(aq)] = [X^2-(aq)] = s

We then have;

Ksp = (2s)^2 * (3s)^3

Ksp = 4s^2 * 9s^3

Ksp = 36s^5

Note that Ksp is known as the solubility product. It is an equilibrum equation that shows the solubility of a solute in water.

3 0
2 years ago
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
ss7ja [257]
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.
7 0
3 years ago
If a mixture containing 0.50 moles of N2 and 1.8 moles of H2 is allowed to react according to the equation N2 3H2 2NH3 Group of
Lelechka [254]

Answer: hydrogen is the limiting reactant.

Explanation:

We have the equation \text{N}_{2}+3\text{H}_{2} \longrightarrow 2\text{NH}_{3}.

This means that for every mole of nitrogen consumed, 3 moles of hydrogen are consumed.

  • Considering the nitrogen, the reaction can occur 0.50 times.
  • Considering the hydrogen, the reaction can occur 1.8/3 = 0.6 times.

Therefore, <u>hydrogen</u> is the limiting reactant.

7 0
2 years ago
The energy of a photon is ________ proportional to its wavelength. The energy of a photon is ________ proportional to its freque
topjm [15]

Answer: Inversely  ,   Directly

Explanation:

The energy of a photon is inversely proportional to its wavelength and directly proportional to its frequency.

As can be seen from this equation;

E = hv  = h c / ∧

Where E = Energy of a photon

           v = Frequency

           h = Planck Constant

           c = speed of light

           ∧  = Wave length

4 0
3 years ago
A student investigates the properties of an unknown liquid substance in a beaker. The student finds the substance has a mass of
shtirl [24]

Answer:

The substance is a mixture because it left a white powder in the beaker when boiled.

Explanation:

8 0
2 years ago
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