All categories

2 years ago

Class 9 Chapter: Structure of the Atom What are the alpha particles compared to?Why?

1 answer:

7 0

Alpha particles are highly ionising because of their double positive charge, large mass (compared to a beta particle) and because they are relatively slow. They can cause multiple ionisations within a very small distance.

You might be interested in

Draw the ring chain of isomer of propene ?

aksik [14]

Explanation:

Molecular formula for Propene = C3H6

The isomer of propene is cyclopropane.

(Draw a triangle to show that it is cyclopropane)

4 0

2 years ago

Be sure to answer all parts. Express the rate of reaction in terms of the change in concentration of each of the reactants and p

Tanzania [10]

Answer : The [H] is increasing at the rate of 0.36 mol/L.s

Explanation :

The general rate of reaction is,

$aA+bB\rightarrow cC+dD$

Rate of reaction : It is defined as the change in the concentration of any one of the reactants or products per unit time.

The expression for rate of reaction will be :

$\text{Rate of disappearance of A}=-\frac{1}{a}\frac{d[A]}{dt}$

$\text{Rate of disappearance of B}=-\frac{1}{b}\frac{d[B]}{dt}$

$\text{Rate of formation of C}=+\frac{1}{c}\frac{d[C]}{dt}$

$\text{Rate of formation of D}=+\frac{1}{d}\frac{d[D]}{dt}$

$Rate=-\frac{1}{a}\frac{d[A]}{dt}=-\frac{1}{b}\frac{d[B]}{dt}=+\frac{1}{c}\frac{d[C]}{dt}=+\frac{1}{d}\frac{d[D]}{dt}$

From this we conclude that,

In the rate of reaction, A and B are the reactants and C and D are the products.

a, b, c and d are the stoichiometric coefficient of A, B, C and D respectively.

The negative sign along with the reactant terms is used simply to show that the concentration of the reactant is decreasing and positive sign along with the product terms is used simply to show that the concentration of the product is increasing.

The given rate of reaction is,

$2D(g)+3E(g)+F(g)\rightarrow 2G(g)+H(g)$

The expression for rate of reaction :

$\text{Rate of disappearance of }D=-\frac{1}{2}\frac{d[D]}{dt}$

$\text{Rate of disappearance of }E=-\frac{1}{3}\frac{d[E]}{dt}$

$\text{Rate of disappearance of }F=-\frac{d[F]}{dt}$

$\text{Rate of formation of }G=+\frac{1}{2}\frac{d[G]}{dt}$

$\text{Rate of formation of }H=+\frac{d[H]}{dt}$

$\text{Rate of reaction}=-\frac{1}{2}\frac{d[D]}{dt}=-\frac{1}{3}\frac{d[E]}{dt}=-\frac{d[F]}{dt}=+\frac{1}{2}\frac{d[G]}{dt}=+\frac{d[H]}{dt}$

Given:

$-\frac{d[D]}{dt}=0.18mol/L.s$

As,

$-\frac{1}{2}\frac{d[D]}{dt}=+\frac{d[H]}{dt}=0.18mol/L.s$

and,

$+\frac{d[H]}{dt}=2\times 0.18mol/L.s$

$+\frac{d[H]}{dt}=0.36mol/L.s$

Thus, the [H] is increasing at the rate of 0.36 mol/L.s

5 0

2 years ago

What pressure is required to reduce 40 ml of a gas at standard conditions to 20 ml at a temperature of 21?c? answer in units of

ElenaW [278]

If you need half the volume, you need double the pressure (V * p). Normal air pressure in the atmosphere is 101300 Pa so that means you need double that, thus 202600 Pa (or 2,026 bars)

4 0

2 years ago

Webb has calculated the percent composition of a compound. How can he check his result?

fenix001 [56]

Webb has calculated the percent composition of a compound. He can check his result by adding them to see if they equal up to 100. Why? Well, percent composition tells the quantity of elements with 100 as a base of total amount. This means that it will have to add to 100 to check the result. You would add up all of the values of percent composition of elements to see if they equal 100, and if they do, the results are accurate.

Your final answer: Webb can check his result by seeing if they add up to 100, considering that is the base total quantity.

7 0

1 year ago

2. A 10 kg ball is rolled down a rail from a height of 20 m. What is the velocity at the bottom of the

solmaris [256]

Answer:

19.8m/s

Explanation:

Given parameters:

Mass of the ball = 10kg

Height of the rail = 20m

Unknown:

Velocity at the bottom of the rail = ?

Solution:

The velocity at the bottom of the rail is its final velocity.

Using the appropriate motion equation, we can find this parameter;

V² = U² + 2gH

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

H is the height

the ball was rolled from rest, U = 0

V² = O² + 2 x 9.8 x 20

V = 19.8m/s

3 0

2 years ago