In 1860, Chemists could make which of the following statements about the known chemical elements?

3. What is the formula for the compound formed from the magnesium ion and nitrate?

bija089 [108]

Answer:

D.) Mg(NO₃)₂

Explanation:

Since magnesium (Mg) is a metal and nitrate (NO₃) is a polyatomic anion, they would combine to form an ionic compound. Magnesium would form the cation Mg²⁺ because it generally has 2 valence electrons. Nitrate always has a -1 charge.

In order for the overall compound to be neutral (have a charge of 0), there must be one Mg²⁺ and two NO₃⁻ ions in the compound (+2 + (-1) + (-1) = 0).

Therefore, the formula for the compound formed is Mg(NO₃)₂.

8 0

2 years ago

The atom with the same number of neutrons as 12C is 9Be. 11B. 13C. 14N.

julia-pushkina [17]

Answer : The atom with the same number of neutrons as $^{12}C$ is, $^{11}B$

Explanation :

The given atom is, $^{12}C$

Atomic mass number = 12

Atomic number = 6

Atomic number = Number of protons = Number of electrons = 6

Number of neutrons = Atomic mass number - Atomic number = 12 - 6 = 6

Now we have to determine the number of neutrons in the given options.

In atom, $^{9}Be$

Atomic mass number = 9

Atomic number = 4

Atomic number = Number of protons = Number of electrons = 4

Number of neutrons = Atomic mass number - Atomic number = 9 - 4 = 5

In atom, $^{11}B$

Atomic mass number = 11

Atomic number = 5

Atomic number = Number of protons = Number of electrons = 5

Number of neutrons = Atomic mass number - Atomic number = 11 - 5 = 6

In atom, $^{13}C$

Atomic mass number = 13

Atomic number = 6

Atomic number = Number of protons = Number of electrons = 6

Number of neutrons = Atomic mass number - Atomic number = 13 - 6 = 7

In atom, $^{14}N$

Atomic mass number = 14

Atomic number = 7

Atomic number = Number of protons = Number of electrons = 7

Number of neutrons = Atomic mass number - Atomic number = 14 - 7 = 7

Therefore, the atom with the same number of neutrons as $^{12}C$ is, $^{11}B$

6 0

3 years ago

You are given a sample of an element with ONE valence electron.

Gnoma [55]

Answer:

the amount of valence electron, cna be found in the periodic table, which is called the atomic number which is top of the symbol

hope this helps!!! best fo luck to you

5 0

2 years ago

On Earth, the three most common states of matter are Solid, Liquid, and Gas.

julsineya [31]

TRUE you are correct but the earth is also made up of papyrus, an element.

3 0

3 years ago

Read 2 more answers

A 0.15 m aqueous solution of a weak acid has a freezing point of -0.31 °C. What is the percent ionization of this weak acid at t

tensa zangetsu [6.8K]

Answer:

11%

Explanation:

1) Calculate van 't Hoff factor:

Δt = i Kf m

0.31 = i (1.86) (0.15)

i = 1.111

2) Calculate value for [H+]:

CCl3COOH ⇌ H+ + CCl3COO¯

total concentration of all ions in solution equals:

(1.11) (0.15) = 0.1665 m

This is a molality, but we will act as if it a molarity since we will assume the density of the solution is 1.00 g/cm3, which makes the molarity equal to the molality.

0.1665 = (0.15 − x) + x + x

x = 0.0165 M

3) Calculate the percent dissociation:

0.0165/ 0.15 = 11 %

4 0

3 years ago