Look at the image pls. The question is there

. What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?

erica [24]

Moles He = 7.83 x 10^24 / 6.02 x 10^23 =13.0

mass He = 13.0 mol x 4.00 g/mol = 52.0 g

6 0

3 years ago

What is meant by the term chemical reaction

pantera1 [17]

Answer:

<h3> $\huge{ \underline{ \underline { \bold{ \sf{ \orange{See \: below}}}}}}$ </h3>

Explanation:

▪️ $\underline{ \bold{ \sf{ \blue{Chemical \: reaction}}}}$

⇒The composition , decomposition or displacement of molecules of matter during chemical change is called chemical reaction.

▪️ $\underline{ \bold{ \sf{ \purple{ \: Further \: more \: explanation}}}}$

Various conditions bring about these changes. The chemical reactions are represented by chemicalequation. The compounds or elements that take part in chemical reaction are called reactant. They are written at the left side of an arrow that represent a change while the compound or elements that formed after the chemical change are called product. They are written at the right side of the arrow.

▪️ $\underline{ \bold{ \sf{ \purple{For \: example}}}}$

When nitrogen reacts with hydrogen to form ammonia :

Nitrogen + Hydrogen ⇒ Ammonia

N₂ + 3H₂ ⇒ 2NH₃

Presentation of a chemical reaction in the form of equation is called chemical equation . Chemical equation may be word equations or formula equations.

Hope I helped!

Best regards!!

3 0

2 years ago

PLEASE HELPPPPP!!!!!!!

marin [14]

Boiling water is a physical change, because it is changing state of matter, there is a controllable temperature change, and you can change it back.

Frying the egg white is a chemical change, because there is a change of matter, controllable temperature change, but you CAN'T change it back.

8 0

3 years ago

A galvanic cell consists of one half-cell that contains Ag(s) and Ag+(aq), and one half-cell that contains Cu(s) and Cu2+(aq). W

Agata [3.3K]

Answer : The 'Ag' is produced at the cathode electrode and 'Cu' is produced at anode electrode under standard conditions.

Explanation :

Galvanic cell : It is defined as a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy. It is also known as the voltaic cell or electrochemical cell.

In the galvanic cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode.

We are taking the value of standard reduction potential form the standard table.

$E^0_{[Ag^{+}/Ag]}=+0.80V$

$E^0_{[Cu^{2+}/Cu]}=+0.34V$

In this cell, the component that has lower standard reduction potential gets oxidized and that is added to the anode electrode. The second forms the cathode electrode.

The balanced two-half reactions will be,

Oxidation half reaction (Anode) : $Cu(s)\rightarrow Cu^{2+}(aq)+2e^-$