describe three characteristics that trees used to build treehouses should have. why are these characteristics essential

Which is a substance that is made up of only one type of atom?

deff fn [24]

The answer is element

5 0

3 years ago

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Which notation represents the largest atomic radius?

Darina [25.2K]

Answer:

Calcium(Ca)

Explanation:

Atomic radius is the distance from the nucleus of an atom the outermost energy shell or energy level.
The atomic radii of metals are greater than the ionic radii since metals form ions by losing electrons.
Calcium atom has a larger atomic radius compared to magnesium atom because it has more energy levels. Calcium atoms have four energy levels while magnesium atoms have three energy levels.

7 0

3 years ago

For the Earth's atmosphere, section number two in the pie graph BEST represents the percentage of A) argon B) oxygen C) nitrogen

larisa86 [58]

-Oxygen

According to Google these are the percentages of the Earths Atmosphere

1 78% - Nitrogen

2 21% - Oxygen

3 0.9% - Argon

4 0.3 - Carbon Dioxide with very small percentage of other elements.

3 0

3 years ago

Can anyone teach me what is criss cross method in chemistry

Solnce55 [7]

Answer:

In the criss-cross method, the numerical value of the ion charge of the two atoms are crossed over, which becomes the subscript of the other ion. Using this technique, we will write the chemical formula of the given compounds.

Criss cross the absolute values to give Al2O3. To find the formula for magnesium oxide:- The oxidation number of Mg is +2 and oxygen is -2. Criss cross the absolute values to give Mg2O2In this example there is a common factor of 2 so divide by 2 to give MgO.

8 0

2 years ago

(5 points)

ExtremeBDS [4]

Answer 2 : The given electronic configuration for a neutral atom of phosphorous in its ground state is incorrect.

Explanation :

A neutral atom of phosphorous has 15 electrons.

The given electronic configuration is incorrect.

The reason is, According to Aufbau principle, the electrons will be first filled in the sub-shell having lower orbital energy. As from the given configuration, 3p sub-shell has lower orbital energy than 4s sub-shell. So, the electrons will be filled in 3p sub-shell first. Hence, the ground state electronic configuration of neutral atom of phosphorous is,

$1s^22s^22p^63s^23p^3$

Answer 3 :

Element Rubidium Magnesium Aluminium

Symbol Rb Mg Al

Group number 1 2 13

Number of valence 1 2 3

electrons

The order of general reactivity on the basis of number of valence electrons.

Rb > Mg > Al

Reason : The reactivity is determined by the number of electrons present in the outermost shell that means the element which have 1 valence electron will be more reactive because they can easily lose electrons.

5 0

2 years ago