The index of refraction of a material medium must be less than 1 true or flase

Answer: An atom valence electron shell determines its chemical reactivity.

Explanation:

An atom's valence electron shell determines its chemical reactivity. The amount of electrons in the outermost shell of an atom is its valence electron and it determines how reactive the atom is.

The reactivity of an atom depends on the number of electrons in its outermost shell. Atoms that has their outermost electrons full e.g noble gases like argon, krypton etc are unreactive because there is no room for the atom to donate or accept any electron.

Elements like sodium and chlorine are reactive because they possesses 1 and 7 electrons in their outermost shell respectively as such they can donate and accept electrons making them reactive elements.

The valence electron shell of an atom determines its chemical reactivity. This is due to the role these outermost electrons play in the formation of chemical bonds. Atoms aim to achieve a stable state, typically with eight electrons in their outermost shell, through accepting, donating, or sharing electrons.

The correct answer to the multiple choice question about the atom's valence electron shell is '2. determines its chemical reactivity'. The outermost shell of an atom is known as the valence shell. This shell, holding the valence electrons, is essential in determining an atom's chemical reactivity. This is because it's the valence electrons that are engaged in the formation of chemical bonds.

Chemical reactivity refers to the ease with which an atom gains, loses, or shares electrons. Stable atoms, like helium or larger atoms with eight electrons, are less likely to participate in chemical reactions. They already have a filled valence shell. However, other atoms, those with less than eight electrons, will strive to complete their outer shell by interacting with other atoms, either accepting, donating or sharing electrons to achieve stability.

Importantly, not all elements have enough electrons to completely fill their outermost shells and so they form chemical bonds by sharing, accepting, or donating electrons to other atoms. The formation of these bonds is largely determined by what is often referred to as the 'octet rule', which states that atoms seek to fill or have eight electrons in their outermost electron shell to achieve greater stability.

For more such questions on valence electron, click on:

brainly.com/question/19129319

#SPJ3

Answer:

plasma

Expl

This other guy said it was plasma

The maximum height that the rock attains is : 7.42 m

Given data :

Vi = 15.0 m/s

uk = 0.425

angle made by roof ( θ ) = 42.0°

Calculating the maximum height reached by the rock

First step : calculate the deceleration of the rock

a = g*sinθ + uk * g * cosθ

  = 9.8 * sin 42° + 0.425 * 9.8 * cos 42°

  = 9.65 m/s²

Applying motion formula

v² = u² + 2as

    = 15² - 2 * 9.65 * 10

 v  = 5.66 m/s

Initial height attained ( h₁ ) =  10 sin θ

                                           =  10 * sin 45°

                                           =  6.69 m

considering vertical height

V (y) = v sin θ

       = 5.66 sin 42

       = 3.79 m/s

Next step : Calculate  height ( h₂ )

v² = u² + 2 a s

0 = 3.79² - 2 * 9.8 * h₂

therefore :  h₂ = 0.73 m

The maximum height attained by the rock ( H ) = h₁ + h₂

                                                                              = 6.69 + 0.73 = 7.42 m

Hence we can conclude thatThe maximum height that the rock attains is : 7.42 m

Learn more about projectile : brainly.com/question/24216590

Answer:

h = 7.42 m

Explanation:

deceleration of the rock

a = 9.65 m/s²

using formula

v² = u² + 2 a s

v² = 15² - 2×9.65 × 10

v = 5.66 m/s

the height attained is

h₁ =  10 sin θ

   = 10 sin 42

   = 6.69 m

now with vertical velocity it will reach to the height h₂

v y = v sin θ

     = 5.66 sin 42

     = 3.79 m/s

height is

v² = u² + 2 a s

0 = 3.79² - 2 × 9.8 ×h₂

h₂ = 0.73 m

the maximum height is

h = h₁ + h₂

  = 6.69 + 0.73

h = 7.42 m