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2 years ago

What allowed Mendeleev to make predictions of undiscovered elements

2 answers:

7 0

Predictions using gaps Mendeleev left gaps in his table to place elements not known at the time. By looking at the chemical properties and physical properties of the elements next to a gap, he could also predict the properties of these undiscovered elements.

Andrej [43]2 years ago

3 0

Answer:

he predicted the properties from known elements above and belws the unknown in the same group

Explanation:

What allowed Mendeleev to make predictions of undiscovered elements

He realized that an element on this table with one known element above it and one known element below it had to have properties between the two known elements

How did Mendeleev predict gallium and germanium?

Based on gaps in the periodic table Mendeleev deduced that in these gaps belonged elements yet to be discovered. Based on other elements below and above in the same group he predicted the existence of eka-aluminum, eka-boron, and eka-silicon, later to be named gallium (Ga), scandium (Sc), and germanium (Ge).

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Which would most likely be joined by an ionic bond?

KATRIN_1 [288]

An ionic bond is composed of a cation and anion, which are charged ions. You cannot have atoms with ionic bonds, because there is no opposite attraction between charges due to atoms having a net nuclear charge of zero. Therefore, a cation and anion would most likely be joined by an ionic bond.

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3 years ago

How many grams are in 4 moles of aluminum phosphate

vladimir2022 [97]

Answer:

487.8116

Explanation:

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3 years ago

Read 2 more answers

A solution is made by dissolving 0.0150 mol of HF in enough water to make 1.00 L of solution. At 26 °C, the osmotic pressure of

Alex777 [14]

Given:
M = 0.0150 mol/L HF solution
T = 26°C = 299.15 K
π = 0.449 atm

Required:
percent ionization

Solution:
First, we get the van't Hoff factor using this equation:
π = i MRT
0.449 atm = i (0.0150 mol/L) (0.08206 L atm / mol K) (299.15 K)
i = 1.219367

Next, calculate the concentration of the ions and the acid.
We let x = [H+] = [F-]
[HF] = 0.0150 - x

Adding all the concentration and equating to iM
x +x + 0.0150 - x = <span>1.219367 (0.0150)
x = 3.2905 x 10^-3

percent dissociation = (x/M) (100) = (3.2905 x 10-3/0.0150) (100) = 21.94%

Also,
percent dissociation = (i -1) (100) = (</span><span>1.219367 * 1) (100) = 21.94%</span>

7 0

3 years ago

Write a net ionic equation for the overall reaction that occurs when aqueous solutions of nitrous acid and sodium hydroxide are

Bess [88]

Answer:

H+(aq) + OH-(aq) → H2O(l)

Explanation:

Step 1: Data given

nitrious acid = HNO3

sodium hydroxide = NaOH

Step 2: The unbalance equation

HNO3(aq) + NaOH(aq) →NaNO3(aq) + H2O(l)

The net ionic equation, for which spectator ions are omitted - remember that spectator ions are those ions located on both sides of the equation - will , after canceling those spectator ions in both side (Ba^2+ and Br-), look like this:

H+(aq) + NO3-(aq) + Na+(aq) + OH-(aq) →Na+(aq) +NO3(aq) + H2O(l)

H+(aq) + OH-(aq) → H2O(l)

7 0

3 years ago

To measure the speed of a car, we use miles per hour (miles/hour or mi/h or mph). To measure the rate of a reaction we use molar

arsen [322]

Answer:

Part A: 47.8 mi/h

Part B: 0.072 M/s

Part C: 0.144 M/s

Explanation:

Part A

The average speed or velocity (V) is the variation of the space divided by the variation of the time:

V = (241 - 2)/(8 -3)

V = 47.8 mi/h

Part B

As Part A, the average rate (r) of formation of I2 is the variation of the concentration divided by the variation of time:

r = (1.83 - 1.11)/(15 - 5)

r = 0.072 M/s

Part C

The rates of the substances are proportional of their number of moles (n) which are their coefficient, so:

rI2/nI2 = rHCl/nHCl

0.072/1 = rHCl/2

rHCl = 2*0.072

rHCl = 0.144 M/s

7 0

3 years ago