If you look on the periodic table you will see the top group elements depending on how the elements relate to each in the column. All of the elements in that column show they all have 1 electron in their valence shell. Some of the chemicals in that family or group are Sodium, Lithium, Potassium. The are very reactive because they only have one electron and what 7 more to become stable.
Answer:
The correct answer is option A: they are isotopes.
Explanation:
From atom X we know that the number of protons is 7 and the number of neutrons is 7 and from atom Z we know that the number of protons is 7 and the number of neutrons is 8.
Since the number of protons of atom X and atom Z is the same, we have that atom X and atom Z is the same element. The difference in the number of neutrons tells us that atom X and atom Z are isotopes. Remember that an isotope is one element that has atoms with different numbers of neutrons.
The mass number is given by:
Where <em>n</em> is the number of neutrons and <em>p </em>is the number of protons.
For atom X and atom Z we have:
Hence, they have a different mass number.
We know that the element with 7 protons is nitrogen. The first isotope is 
and the second isotope is 
. Both isotopes are stables (they are not radioactive).
Therefore, the correct answer is option A: they are isotopes.
I hope it helps you!
The kinetic energy and gravitational potential energy changes during its movement from ground to the top height.
<h3>What happens to kinetic and potential energy while motion?</h3>
When the ball moves upward, its gravitational potential energy is increases and kinetic energy begins to decrease but when the ball falls towards the earth, its gravitational potential energy is transformed into kinetic energy. When the ball collides with the ground, the kinetic energy is transformed into other forms of energy.
Learn more about kinetic energy here: brainly.com/question/20658056
A geological fold<span> occurs when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation.
So A fold is a Bend? in a rock. Maybe.
</span>A fault<span> is a planar fracture or discontinuity in a volume of </span>rock<span>, across which there has been significant displacement as a result of </span>rock<span>-mass movement.</span>
The answer is: " 208 g " .
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Explanation:
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The formula/ equation for density is:
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D = m / V ; That is, "mass divided by volume" ;
Density is expressed as:
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"mass per unit volume"; in which the "mass" is expressed in units of "g" ("grams") ; and the "unit volume" is expressed in units of:
"cm³ " or "mL";
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{Note the exact equivalent: 1 cm³ = 1 mL }.
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→ The formula is: " D = m / V " ;
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in which:
"D" refers to the "density" (see above), which is: "8.9 g/cm³ " (given);
"m" refers to the "mass" , in units of "g" (grams), which is unknown; and we want to find this value;
"V" refers to the "volume", in units of "cm³ " ;
which is: "23.4 cm³ " (given);
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We want to find the mass, "m" ; so we take the original equation/formula for the density:
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D = m / V ;
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And we rearrange; to isolate "m" (mass) on ONE side of the equation; and then we plug in our known/given values;
to solve for "m" (mass); in units of "g" (grams) ;
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Multiply each side of the equation by "V" ;
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V * { D = m / V } ; to get:
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V * D = m ; ↔ m = V * D ;
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Now, we plug in the given values for "V" (volume) and "D" (density) ; to solve for the mass, "m" ;
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m = V * D ;
m = (23.4 cm³) * (8.9 g / 1 cm³) = (23.4 * 8.9) g = 208.26 g ;
→ Round to "208 g" (3 significant figures);
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The answer is: " 208 g " .
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