Minerals in igneous rocks that form from lava are large because lava cools slowly.

Beryllium exhibits diagonal relationship with- * (a) Al (b) B (c) Mg (d) Si

Dmitriy789 [7]

Answer:

A)Al

Explanation:

Both metals have a tendency to form covalent bonds with molecules

they both form chlorine bridged structures in vapour phase

both are resistant to action of acid due to the formation of protective film of oxides on their surface

6 0

2 years ago

A bond between H and o

Salsk061 [2.6K]

We can exemplify with H2O (water)
H= nonmetalic
O= Nonmetalic
A bond with nonmetalic and nonmetalic is covalent bond.
Hope it helps!!
#MissionExam001

3 0

3 years ago

20.0 g of Nitrogen is produced when oxygen gas reacts with NO gas. 29.8 L of oxygen is required at STP to produce this 20.0 g of

fiasKO [112]

The statement is false as 85675 grams of nitrogen dioxide is produced instead of 20 grams.

Explanation:

Balance equation for the reaction:

2NO + $O_{2}$ ⇒ 2N $O_{2}$

Data given:

mass of nitrogen produced = 20 gram

mass of oxygen = 29.8 litres or 29800 grams

0xygen is the limiting reagent so,

number of moles of oxygen: (atomic mass of 1 mole 32 grams/mole

number of moles = $\frac{mass}{atomic mass of 1 mole}$

putting the values in the equation:

= $\frac{29800}{32}$

= 931.5 moles

1 mole of oxygen reacts to give 2 moles of NO2

931.5 moles of oxygen will give x moles

$\frac{2}{1}$ = $\frac{x}{931.5}$

1862.5 moles of NO2 produced

in grams

mass = number of moles x atomic mass

mass = 1862.5 x 46.00

= 85675 grams

The statement is false as 85675 grams of nitrogen dioxide is produced instead of 20 grams as said in question.

7 0

3 years ago

The work function for metallic potassium is 2.3 eV. Calculate the velocity in km/s for electrons ejected from a metallic potassi

mote1985 [20]

Answer:

932.44 km/s

Explanation:

Given that:

The work function of the magnesium = 2.3 eV

Energy in eV can be converted to energy in J as:

1 eV = 1.6022 × 10⁻¹⁹ J

So, work function = $2.3\times 1.6022\times 10^{-19}\ J=3.68506\times 10^{-19}\ J$

Using the equation for photoelectric effect as:

$E=\psi _0+\frac {1}{2}\times m\times v^2$

Also, $E=\frac {h\times c}{\lambda}$

Applying the equation as:

$\frac {h\times c}{\lambda}=\psi _0+\frac {1}{2}\times m\times v^2$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

m is the mass of electron having value $9.11\times 10^{-31}\ kg$

$\lambda$ is the wavelength of the light being bombarded

$\psi _0=Work\ function$

v is the velocity of electron

Given, $\lambda=260\ nm=260\times 10^{-9}\ m$

Thus, applying values as:

$\frac{6.626\times 10^{-34}\times 3\times 10^8}{260\times 10^{-9}}=3.68506\times 10^{-19}+\frac{1}{2}\times 9.11\times 10^{-31}\times v^2$

$3.68506\times \:10^{-19}+\frac{1}{2}\times \:9.11\times \:10^{-31}v^2=\frac{6.626\times \:10^{-34}\times \:3\times \:10^8}{260\times \:10^{-9}}$

$\frac{1}{2}\times 9.11\times 10^{-31}\times v^2=7.64538\times 10^{-19}-3.68506\times 10^{-19}$

$\frac{1}{2}\times 9.11\times 10^{-31}\times v^2=3.96032462\times 10^{-19}$

$v^2=0.869446\times 10^{12}$

v = 9.3244 × 10⁵ m/s

Also, 1 m = 0.001 km

So, v = 932.44 km/s

5 0

3 years ago

What coefficient is needed to balance the reaction

tensa zangetsu [6.8K]

Answer:

OD. 2HCl

Explanation:

A balanced equation needs the equal # of each element on BOTH sides.

By putting a 2 in front of HCl you now have 2 hydrogens on both sides and 2 chlorines. The Ca and CO3 are already balanced.

5 0

2 years ago