Suppose you increase your walking speed from 7 m/s to 12 m/s in a period of 2 s. What is your acceleration?

Think of a bath sponge. What happens when you squeeze it? How could you explain it from the point of view of the state of the ag

harkovskaia [24]

Answer:

What happens when it is squeezed is that its volume increases, the pressure of the material increases.

Explanation:

This is due to the fact that the elastic modulus of the sponge is high and withstands broad forces without deforming its structure, since the force is made within the proportional limit of its particles without modifying or permanently deforming them, that is why when stopping doing pressure or force on it its shape returns to being the original, this also happens due to the phenomenon of resilience

3 0

3 years ago

Select all the true statements. When an atom gains an electron, it becomes a cation. Anions carry a positive charge. The Cl− and

REY [17]

Answer:

The statements 4 and 5 are true.

Explanation:

1. When an atom gains an electron it becomes negatively charged. This negatively charged species is called anion.

A + e⁻ → A⁻ (anion)

Therefore, the statement 1 is false.

2. An anion is formed when an atom gains an electron and becomes negatively charged. Therefore, an anion is a negatively charged species.

A + e⁻ → A⁻ (anion)

Therefore, the statement 2 is false.

3. The atomic number of chlorine atom Cl is 17 and atomic number of bromine atom Br is 35.

Since, for neutral atom, the atomic number of an atom is equal to the number of electrons present in that atom.

Therefore, the number of electrons in Cl atom is 17 and the number of electrons in Br atom is 35.

When the Cl atom gains one electron it forms Cl⁻ ion and when the Br atom gains one electron it forms Br⁻ ion.

Therefore, the number of electrons in Cl⁻ ion is 17 + 1 = 18 electrons

and the number of electrons in Br⁻ ion is 35 + 1 = 36 electrons

Therefore, Cl⁻ and Br⁻ ions do not have the same number of electrons.

Therefore, the statement 3 is false.

4. When potassium atom (K) loses one electron it forms a positively charged species called potassium cation (K⁺).

K → K⁺ + e⁻

Therefore, the statement 4 is true.

5. The atomic number of Fe atom is 26.

Since, the atomic number of an atom is equal to the number of protons present in that atom.

When the Fe atom loses two electrons to form Fe²⁺ and when the Fe atom loses three electrons to form Fe³⁺ ion, the number of protons remains the same.

Therefore, the ions Fe²⁺ and Fe³⁺ have the same number of protons.

Therefore, the statement 5 is true.

6. The atomic number of copper atom Cu is 29.

Since, for neutral atom, the atomic number of an atom is equal to the number of electrons present in that atom.

Therefore, the number of electrons in Cu atom is 29

When the Cu atom loses one electron it forms Cu⁺ ion and when the Cu atom loses two electrons it forms Cu²⁺ ion.

Cu → Cu⁺ + e⁻ and Cu → Cu²⁺ + 2e⁻

Therefore, the number of electrons in Cu⁺ ion is 29 - 1 = 28 electrons

and the number of electrons in Cu²⁺ ion is 29 - 2 = 27 electrons

Therefore, Cu⁺ ion and Cu²⁺ ion do not have the same number of electrons.

Therefore, the statement 6 is false.

3 0

3 years ago

A 360. mg sample of aspirin, C9H8O4, (molar mass 180. g), is dissolved in enough water to produce 200. mL of solution. What is t

Gemiola [76]

Answer:

Molarity = 0.01 M

Explanation:

Molarity is used to measure the concentration of a solution. It will be same for the whole solution or a small amount of solution if the solution is homogeneous.

So, <u>Molarity of 200 mL of solution = Molarity of 50 mL of solution</u>

$\mathbf{Molarity = \frac{number \ of \ moles \ of \ solute}{Volume \ of \ solution \ (in \ liters)}}$

$\mathbf{Moles = \frac{given \ mass \ of \ compound}{molar \ mass \ of \ compound}}$

given mass of aspirin = 360 mg = 0.36 g

molar mass of aspirin = 180 g

Volume of solution = 200 mL = 0.2 L

$\mathrm{Mole \ of \ Aspirin = \frac{0.36}{180} = \mathbf{0.002 \ moles}}$

$\mathrm{Molarity = \frac{0.002}{0.2} = \mathbf{0.01 \ M}}$

Therefore, Molarity = 0.01 M

7 0

3 years ago

how many moles of gas does it take to occupy 120 liters at a pressure of 2.3 atmospheres and a temperature of 340 K?

dezoksy [38]

Data:

P (pressure) = 2.3 atm
V (volume) = 120 L
T (temperature) = 340 K
n (number of mols) = ?
R (Gas constant) = 0.082 (atm*L/mol*K)

Formula:

$p*V = n*R*T$

Solving:
$p*V = n*R*T$
$2.3*120 = n*0.082*340$
$276 = 27.88n$
$27.88n = 276$
$n = \frac{276}{27.88}$
$n = 9.89956...\to \boxed{\boxed{n\approx 9.90\:mols}}\end{array}}\qquad\quad\checkmark$

7 0

4 years ago

Calculate the enthalpy change for the reaction 2 hcl → h2 + cl2 1. +184 kj/mol of rxn 2. +428 kj/mol of rxn 3. 0 kj/mol of rxn 4

lesantik [10]

Below is the list of enthalpies of formation of the compounds involved in the chemical reaction.

HCl: -92.3 kJ/mol
H2: 0
Cl2: 0

Both H2 and Cl2 do not have enthaply of formation because they are pure substances.

Since, in the reaction there are 2 moles of HCl,
Enthalphy of formation = enthalpy of products - enthalphy of reactant/s
= 0 - (-92.3)(2) = +184.6 kJ

Hence, the answer is the first choice.

5 0

3 years ago