please help me.......

Answer:

See Below.

Explanation:

This is a conversion problem:

Using the molar mass of Gold (given in a periodic table) which is 196.97g/mol

you have

[tex](3.60*10^-5 g) *\frac{1moles}{196.97g}[/tex]

you always arrange the equation in a way to cancel whatever you don't want (grams) and leave what you do want (moles). Here grams cancel (top and bottom), so you're left with:

[tex]\frac{(3.60*10^-5 g) *(1)}{196.97} = 1.83*10^-7[/tex] moles of Gold

Answer:

number of valence electrons

Explanation:

elements in the same group has same number of valence electrons

Answer:

chemical equation balance.

Explanation:

if you need more explanation , comment.

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{5.25 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 87.2093023...[/tex]

We have the final answer as

Hope this helps you

Answer:

Reactivity

Explanation:

Luster. Ductile, and Malleabillity are all physical.

Answer:

his reaction is the synthesis of Ammonia using Nitrogen and Hydrogen gas.

N

+

H

→

N

H

3

We must remember that Nitrogen and Hydrogen are both diatomic molecules in their standard gas form. This adjusts the equation to

N

2

+

H

2

→

N

H

3

Now we need to adjust coefficients in order to balance the atoms on each side of the equation. Currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

We can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

N

2

+

3

H

2

→

2

N

H

3

This gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.

I hope this was helpful.

Explanation:

Answer:

1N2 + 3H2 →2NH3

Explanation:

Plato answer

Answer:

B- Have new properties after they are mixed

I hope this helps

Answer:

Explanation:

Beta radiations:

mass 1/200 , charge -1, medium penetration

Beta radiations are result from the beta decay in which electron is ejected.

The mass of beta particle is smaller than the alpha particles.

They can travel in air in few meter distance.

These radiations can penetrate into the human skin.

The sheet of aluminum is used to block the beta radiation

Properties of alpha radiation:

mass 4 amu, charge +2, least penetration

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4  and atomic number less than 2 as compared to parent atom the starting atom.

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

Gamma radiations:

mass 0, charge 0, deepest penetration

Gamma radiations are high energy radiations having no mass.

These radiations are travel at the speed of light.

Gamma radiations can penetrate into the many materials.

These radiations are also used to treat the cancer.

Lead is used for the protection  against gamma radiations because of its high molecular density.

The lead apron are used by the person when treated with gamma radiations.

Answer:

There are 6 significant figures

Answer:

6 significant figures

Explanation:

When counting significant figures, start on the left with the first non-zero number. Count all numbers that fall between non-zero numbers. Count all zeros after a 1-9 and after the decimal.

The illustration is an example of surface waves.

Answer:

Explanation:

CaCO₃     +     2HCl     →      CaCl₂    +    CO₂       +       H₂O

100 gm  +  2000 mL of M HCl

Amount of HCl remaining = .1018 M of 16.62 mL

= .1018 x 16.62 mL of M HCl

= 1.69 mL of M HCl

Initial HCl taken = 50 mL of .1035 M HCl

= 5.175 mL of M HCl

HCl reacted = 5.175 - 1.69 mL of M HCl

= 3.485 mL of  M HCl

2000 mL of M HCl reacts with 100 gm of CaCO₃

3.485 mL of M HCl will react with .174 grams of CaCO₃

percentage of calcium carbonate = .174 x 100 / .2027

= 85.84 %

Answer:

A.  Synthesis

B.  Combustion

C.  Single-replacement

D.  Decomposition

Explanation:

A:  Synthesis.  Two reactants are combined to form, or synthesize, one product.

B:  Combustion.  This is the general reaction for combustion.  When something combusts, oxygen must be present.  Carbon dioxide and water must also be produced.

C:  Single-replacement. The oxygen from Fe₂O₃ is moved to K to form K₂O.  Only one thing is being moved, or replaced.

D:  Decomposition.  You have one compound that breaks into, or decomposes, into two products.

Answer:

Ca(CO3) --> CaO + CO2

Zn + H2SO4 --> ZnSO4 + 2H2

Explanation:

^^^

Answer:

STANDARD: 0.085 mi, 450 ft, or 150 yds

METRIC: 0.137 km, 137.16 m, or 13716 cm

Explanation:

Answer:

Explanation:

d

Answer:

D. All it’s mechanical energy is transformed into other forms of energy.

Explanation:

I got it right

Answer:

1.  7.86 × 10⁴ g

2.  7.86 × 10⁴ kg

3.  1.989 × 10¹³ mg

4.  1.989 × 10²⁸ kg

5.  1.989 × 10³³ g

Explanation:

The easiest way to make sure you have the right answer is to convert all units to the same unit.

A.  1.989 × 10¹³ mg = 1.989 × 10¹⁰ g

B.  7.86 × 10⁴ g

C.  1.989 × 10³³ g

D.  7.86 × 10⁴ kg = 7.86 × 10⁷ g

E.  1.989 × 10²⁸ kg = 1.989 × 10³¹

The correct order is B < D < A < E < C

Answer:the positive ionic radius is smaller than the neutral atomic radius

Explanation:

Answer:The positive ionic radius is smaller than the neutral atomic radius.

Explanation: just took the test

Answer:

some zoom in farther

Explanation:

some microscopes zoom in farther than others so we can see even smaller things

Answer:

The Flux N_B = 0

Explanation:

So, we are given the following set of data or parameters which is going to help in solving this particular Question. So, let us take each at a time;

=> "An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface."

=>" 2.0 wt 'Yo ammonia (density of aqueous solution is 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density of 961.7 kg/m3). ''

With the information above, we can determine the N_A(which the question did not specify that we should calculate).

For the value of N_B, it will be equals to zero(0) because the insolubility of water in organic solvent.

Answer:

I think it is synthesis

Answer:

The answer is Synthesis

Explanation:

The two objects combine to make a bigger object

Answer:

A, True

Explanation:

Answer:

E conduct electricity when melted

Explanation:

They can not produce electricity until dissolved/ melted in water

Answer:

Double Displacement Reaction

Explanation:

A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.

Answer:

KOH+Mg(NO3)2

Explanation:

The double replacement reaction will result in:

2KOH(aq) + Mg(NO3)2[tex]\\[/tex](aq)--> 2KNO3(aq) + Mg(OH)2(s)

Solubility rules prove that Mg+OH^- is insoluble and will result in a precipitate (solid)

Answer:

Yes

Explanation:

A atom is made out of 3 elements, protons which are positive charges, electrons which are negative charges that swirl around the atom, and a neutron with a neutral charge. The nucleus of the atom is basically the center of the atom.

Growth hormon somatotropin