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3 years ago

CHEMISTRY:There are 9 rotons & 11 neutrons. What is the atomic number & atomic mass?

Chemistry

1 answer:

ziro4ka [17]3 years ago

5 0

Hey there!

Atomic number is the number of protons.

Atomic mass is the sum of protons and neutrons.

9 + 11 = 20

Your answer is B) The atomic number is 9 & the atomic mass is 20.

Hope this helps!

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I WILL GIVE BRAINLIESTTTT!!!!!

BartSMP [9]

De Broglie's wave equation describes that particles have wave properties. The equation is
λ = h/mv

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λ = ?
h = 6.62607 x 10⁻³⁴<span> J s
m =200 g = 0.2 kg
v = 20 m/s

</span>By substitution,
λ = 6.62607 x 10⁻³⁴ J s / (0.2 kg x 20 m/s)
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3 years ago

How many grams of CaCl₂ should be dissolved in 500.0 mL of water to make a 0.20M solution of CaCl₂?

Butoxors [25]

0.2M means 0.2mol CaCl2/1L solution.

This question didn't give us a density of the solution so needs an assumption that the solution has equal volume to water.

xmol/0.5L=0.2M
x = 0.1

0.1mol of CaCl2 is needed. Ca=40g/mol, Cl=35.5g/mol.
CaCl2 0.1mol = (40+35.5*2)*0.1=11.1g

8 0

3 years ago

rutherford proposed that atoms have positive nuclei. which statement correctly describes the nucleus of an atom? the nucleus con

artcher [175]

The statement that correctly describes the nucleus of the atom is that most of the mass of an atom is located in the nucleus. The nucleus contains neutrons and protons. Rutherford reasoned that all of the atom's positively charged particles were contained in the nucleus and the negatively charged particles were scattered outside the nucleus. Both neutrons and protons are given a mass of one atomic mass unit or amu. Electrons have a mass many times smaller than 1 amu.

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4 years ago

Read 2 more answers

(NH4)3PO4 + Pb(NO3)4. Pb3(PO4)4 + NH4NO3

Dafna1 [17]

4(NH₄)₃PO₄ + 3Pb(NO₃)₄ → Pb₃(PO₄)₄ + 12NH₄NO₃

Explanation:

(NH₄)₃PO₄ + Pb(NO₃)₄ → Pb₃(PO₄)₄ + NH₄NO₃

Balancing this equation;

We simply use a mathematical approach by solving simple algebraic equations.

a(NH₄)₃PO₄ + bPb(NO₃)₄ → cPb₃(PO₄)₄ + dNH₄NO₃

a,b,c and d are the coefficients that will balance the equation;

Conserving N: 3a + 4b = 2d equation 1

H: 12a = 4d

P; a = 4c

O; 4a + 12b = 16c + 3d

Let us make a = 1;

c = $\frac{1}{4}$

d = 3

solving for b;

from (i); 4b = 2d -3a = 2(3) - 3(1) = 3

b = \frac{3}{4}

Now multiply a, b, c and d by 4;

a = 4 , b = 3 , c= 1 and d = 12

4(NH₄)₃PO₄ + 3Pb(NO₃)₄ → Pb₃(PO₄)₄ + 12NH₄NO₃

Learn more:

Balanced equation brainly.com/question/11102790

#learnwithBrainly

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3 years ago

Which of the following are ionic, and which are molecular? (a) Sc2O3 ionic molecular (b) NaI ionic molecular (c) SCl2 ionic mole

tangare [24]

Answer :

Ionic compound : (a), (b), (d), (e), (f), (g) and (h)

Molecular compound : (c)

Explanation :

Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.

Ionic compound are usually formed when a metal reacts with a non-metal.

Covalent compound : It is defined as the compound which is formed by the sharing of electrons between the atoms forming a compound.

The covalent compound are usually formed when two non-metals react.

All the polyatomic ions always form an ionic compound.

Polyatomic ions : It is a charged species that composed of two or more atoms and these charged species are bonded by the covalent bond.

As we know that the molecular compounds are the covalent compounds.

(a) Sc₂O₃

This is an ionic compound because it is made up of scandium metal and oxygen non-metal elements.

(b) NaI

This is an ionic compound because it is made up of sodium metal and iodine non-metal elements.

(c) SCl₂

This is an molecular compound because it is made up of sulfur and chlorine non-metal elements.

(d) Ca(NO₃)₂

This is an ionic compound because it is made up of calcium metal and polyatomic ion $(NO_3^-)$ non-metal elements.

(e) FeCl₃

This is an ionic compound because it is made up of iron metal and chlorine non-metal elements.

(f) LaP

This is an ionic compound because it is made up of lanthanum metal and phosphorous non-metal elements.

(g) CoCO₃

This is an ionic compound because it is made up of cobalt metal and polyatomic ion $(CO_3^{2-})$ non-metal elements.

(h) (NH₄)₂SO₄

This is an ionic compound because it is made up of ammonium ion and sulfate ion.

3 0

3 years ago