Ask question

Ask question

All categories

3 years ago

5

The number that identifies an atom is the same as the number of: *

1 answer:

seropon [69]3 years ago

3 0

Explanation:

atomic number = proton

You might be interested in

Which change will decrease the electric force between two positively charged objects? moving them closer together moving them fa

Nina [5.8K]

Answer:

Moving them farther apart

Explanation:

One can try to change the distance between the two positive charges in such a way that it increases the distance and decreased the electric force.

6 0

3 years ago

Read 2 more answers

What is the chemical formula for Sodium Floride?

UkoKoshka [18]

The chemical formula for Sodium Fluoride is NaF.

8 0

3 years ago

A small sack of sand has a density of 1.5 g/cm3 and a mass of 1500 g. How much space (volume) does the sand occupy?

d1i1m1o1n [39]

The answer would be 1000 cm3

8 0

3 years ago

Read 2 more answers

How is a suspension different from a colloid?

Mashcka [7]

Answer:

Explanation:

Colloidal:

Colloid consist of the particles having size between 1 - 1000 nm i.e, 0.001- 1μm.

The particles in colloid can not be seen through naked eye.

It is homogeneous.

We can not separate the colloidal through the filtration. The pore size of filter paper is 2μm. However it can be separated through the ultra filtration. In ultra filtration the pore size is reduced by soaking the filter paper in gelatin and then in formaldehyde. This is only in case of when solid colloidal is present, if colloid is liquid , there is no solid particles present and ultra filtration can not be used in this case.

Suspension:

The particle size in suspension is greater than 1000 nm.
These particles can seen through naked eye.

It is heterogeneous.
The particles in suspension can be separated through the filtration.

3 0

3 years ago

A first-order reaction has a half-life of 29.8 s . How long does it take for the concentration of the reactant in the reaction t

lutik1710 [3]

Answer : The time taken for the concentration of the reactant in the reaction to fall to one-fourth of its initial value is, 12.4 seconds.

Explanation :

Half-life = 29.8 s

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{29.8s}$

$k=0.0232s^{-1}$

Now we have to calculate the time passed.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $0.0232s^{-1}$

t = time passed by the sample = ?

a = let initial amount of the reactant = x M

a - x = amount left after decay process = $x-\frac{1}{4}\times (x)=\frac{3}{4}\times (X)=\frac{3x}{4}M$

Now put all the given values in above equation, we get

$t=\frac{2.303}{0.0232s^{-1}}\log\frac{x}{(\frac{3x}{4})}$

$t=12.4s$

Therefore, the time taken for the concentration of the reactant in the reaction to fall to one-fourth of its initial value is, 12.4 seconds.

7 0

4 years ago