1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
REY [17]
3 years ago
8

What is the mass number of an atom with 5 proton and 7 neutrons

Chemistry
2 answers:
Xelga [282]3 years ago
8 0
So the element is boron, so its mass number is 12.
Nataly [62]3 years ago
8 0
Its boron and the answer is going to be 12
You might be interested in
What type of bonding occurs in a sample of pure sodium, ? In other words, how is one sodium atom held to another sodium atom? A.
NeX [460]

Answer:

The answer to your question is B. metallic

Explanation:

Covalent bonding is a bond between two nonmetals and the difference in electronegativity is between 0 and 1.7. Sodium could not have this kind of bond because is a metal.

Ionic bonding is a bond between a metal and a nonmetal and the difference of electronegativity is higher than 1.7. Sodium can have this kind of bond it is necessary one nonmetal.

Metallic, sodium has a metallic bond because this bond is characteristic of metals.

4 0
3 years ago
Which set of numbers gives the correct possible values of I for n = 2?
Marysya12 [62]

Answer:

0,1

Explanation:

There are four quantum numbers:

Principal quantum number (n)

Azimuthal quantum number (l)

Magnetic quantum number (ml)

Spin quantum number (ms)

All these four quantum numbers gives complete information about an electron like its spin, shells, subshells and orbitals.

For example:

If n=2 than possible sets of quantum numbers are:

Azimuthal quantum number (l)

The azimuthal quantum number describe the shape of orbitals. Its value for s, p, d, f... are 0, 1, 2, 3. l= n-1

(n-1)

2-1 = 1

For n=2 there are two subshell s and p.

s = 0

p= 1

Magnetic quantum number (ml)

It describe the orientation of orbitals. Its values are -l to +l. For l=1  the ml will be  -1 0 +1

Spin quantum number (ms)

The spin quantum  number tells the spin of electron either its clock wise (+1/2) or anti clock wise (-1/2).

If the electron is added in full empty orbital its spin will be +1/2 because it occupy full empty. If electron is already present and another electron is added then its spin will be -1/2.

4 0
3 years ago
NO LINKSSS PLEASE!!!
Temka [501]

Answer: a

Explanation:

are u a male or female

7 0
2 years ago
Read 2 more answers
g Sucrose (C12H22O11), a nonionic solute, dissolves in water (normal freezing/melting point 0.0°C) to form a solution. If some u
DIA [1.3K]

Answer:

15.4 g of sucrose

Explanation:

Formula to be applied for solving these question: colligative property of freezing point depression. → ΔT = Kf . m

ΔT = Freezing T° of pure solvent - Freezing T° of solution

Let's replace data given: 0°C - (-0.56°C) = 1.86 C/m . m

0.56°C / 1.86 m/°C = m → 0.301 mol/kg

m → molality (moles of solute in 1kg of solvent)

Our mass of solvent is not 1kg, it is 150 g. Let's convert it from g to kg, to determine the moles of solute: 150 g. 1kg/1000g = 0.150 kg

0.301 mol/kg .  0.150kg = 0.045 moles.

We determine the mass of sucrose, by the molar mass:

0.045 mol . 342 g/1mol = 15.4 g

4 0
3 years ago
2 HI(g) ⇄ H2(g) + I2(g) Kc = 0.0156 at 400ºC 0.550 moles of HI are placed in a 2.00 L container and the system is allowed to rea
Alex_Xolod [135]

<u>Answer:</u> The concentration of hydrogen gas at equilibrium is 0.0275 M

<u>Explanation:</u>

Molarity is calculated by using the equation:

\text{Molarity}=\frac{\text{Number of moles}}{\text{Volume of solution (in L)}}

Moles of HI = 0.550 moles

Volume of container = 2.00 L

\text{Initial concentration of HI}=\frac{0.550}{2}=0.275M

For the given chemical equation:

                          2HI(g)\rightleftharpoons H_2(g)+I_2(g)

<u>Initial:</u>                  0.275

<u>At eqllm:</u>           0.275-2x      x         x

The expression of K_c for above equation follows:

K_c=\frac{[H_2][I_2]}{[HI]^2}

We are given:

K_c=0.0156

Putting values in above expression, we get:

0.0156=\frac{x\times x}{(0.275-2x)^2}\\\\x=-0.0458,0.0275

Neglecting the negative value of 'x' because concentration cannot be negative

So, equilibrium concentration of hydrogen gas = x = 0.0275 M

Hence, the concentration of hydrogen gas at equilibrium is 0.0275 M

4 0
3 years ago
Other questions:
  • A cubic piece of metal measures 2.50 cm on each edge. If the metal is nickel, whose density is 8.90 g/cm3, what is the mass of t
    5·1 answer
  • Density Calculations
    12·1 answer
  • You record a %T of 85 from a Spec 20.<br><br> This is equivalent to what absorbable level?
    15·1 answer
  • 13. What is H20 more commonly known as?
    8·2 answers
  • Given that the concentration of myosin is 25pmol·L−1 and Rmax(Vmax)=208pmol·L−1·s−1 , determine the turnover number of the enzym
    14·1 answer
  • Calculate the molar mass of a gaseous substance if 0.125 g of the gas occupies 93.3 mL at STP.
    13·1 answer
  • The central atom in the chlorite anion, ClO2- is surrounded by: Question 5 options: one bonding and three unshared pairs of elec
    9·1 answer
  • How to find the number of moles in a molecule of water
    8·1 answer
  • Why does fluorine have the highest ionization energy
    10·1 answer
  • A scientist claims to have discovered an element with 30 protons in its nucleus. He determines it has 60 electrons. Why is his i
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!