All categories

2 years ago

What does the atomic number of an atom tell us?

Physics

2 answers:

blondinia [14]2 years ago

8 0

Answer:

The number of protons in the atom!

Explanation:

Zepler [3.9K]2 years ago

3 0

Explanation:

The atomic number (Z) of an element is the number of protons in the nucleus of each atom of that element. This means that the number.

That means 12.01 grams of carbon contains 6.0225*1023 atoms of carbon. If you divide the atomic weight by Avogadro's number, you get the mass of one atom. In the case of carbon, that ends up being 0.000000000000000000000019942 grams.

The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons.

The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.

You might be interested in

Astronaut Sarah leaves Earth in a spaceship at a speed of 0.280c relative to Earth. Sarah's destination is a star-system 12.5 li

Usimov [2.4K]

Answer:

L= 12 light years

Explanation:

for length dilation we use the formula

$L=L_0\sqrt{1-\frac{v^2}{c^2} }$

now calculating Lo

Lo = 12.5×365×24×3600×3×10^8

= 1.183×10^17 m

now putting the values of v and Lo in the above equation we get

$L=1.183\times10^{17}\sqrt{1-\frac{0.28c^2}{c^2} }$

= 1.136×10^17 m

L= $= \frac{1.136\times10^{17}}{365\times24\times3600\times3\times10^8}$ m

so L= 12 light years

8 0

3 years ago

Starting from rest, how far will a brick fall if it is going 15 m/s and accelerates at a rate of 9.8 m/s2?

masha68 [24]

Answer:

11.48 m

Explanation:

A brick starts from rest and gains a speed of 15 m/s and accelerates at 9.8 m/s^2

u = 0

v= 15

a= 9.8

s= ?

V^2 = U^2 + 2as

15^2 = 0^2 + 2 × 9.8×s

225= 19.6s

s= 225/19.6

s = 11.48m

Hence the brick will fall 11.48 m

7 0

3 years ago

A visible light has a wavelength of 727.3 nm. Determine its frequency, energy per photon, and color.

Snezhnost [94]

Answer:

$f=4.12\times 10^{14}\ Hz$ and $E=2.73\times 10^{-19}\ J$

Explanation:

The wavelength of a visible light is 727.3 nm.

$727.3\ nm=727.3 \times 10^{-9}\ m$

The formula is as follows :

$c=f\lambda$

f is the frequency of the visible light

$f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{727.3 \times 10^{-9}}\\\\f=4.12\times 10^{14}\ Hz$

Energy of a photon is given by :

E = hf, h is Planck's constant

$E=6.63\times 10^{-34}\times 4.12\times 10^{14}\\\\E=2.73\times 10^{-19}\ J$

Red color has a frequency of $4.12\times 10^{14}\ Hz$ and energy per photon is $2.73\times 10^{-19}\ J$ .

3 0

2 years ago

When a second student joins the first, the height difference between the liquid levels in the right and left pistons is 40 cm .

vlada-n [284]

Answer:

m = 56.5 kg

Explanation:

Since the addition of mass on one piston caused a change in pressure head at the other. Diameter of the piston calculated is used as 0.46 m

Δm*g / Area = p * g * Δh ..... Eq1

$m = \frac{p*h*A}{g}$

$m = \frac{850 * 0.4 * pi*0.46^2}{4*9.81}\\\\m= 56.5 kg$

8 0

2 years ago

Young's Modulus refers to changes in the a Volume b- Length c- Body layers

Novosadov [1.4K]

Explanation:

Young' modulus is the ratio of normal stress to the longitudinal strain. Mathematically, it is given by :

Normal stress is given by force per unit area. Longitudinal strain is the change in length per unit original length.

The mathematical definition of Young's modulus is given by :

$Y=\dfrac{F/A}{\Delta L/L}$ ..........(1)

Where

$\Delta L$ is the change in length

F is the force

A is the area of cross section

So, the Young's modulus refers to the change in length of the object. Hence, the correct option is (b) "length".

8 0

3 years ago