Answer:
B
Explanation:
We are talking about the periodic table in which elements where put under different rows and columns according to their atomic number (number of protons) in ascendant order.
In rows or periods we can find trends in some properties like atomic radius, electronegativity, etc...). So they are not similar in size. Option A is a false statement.
Also, they were organized in groups or columns according to their similar electronic configuration and chemical properties (like noble gases, halogens, etc...) This means option B is the correct statement.
One minus two equals negative one and three minus five equals negative two
Answer:
Elaina's scientific investigation is missing controlled variables.
Explanation:
A good scientific investigation should vary only the factor that is studied (the speed of the music. All other factors should be kept constant.
She hasn’t controlled for <em>volume</em>. The volume of the music may affect the rate at which the listener’s heart rate will increase. She should have measured each person’s pulse after the same period of listening.
She hasn’t controlled for <em>age</em>. A grandmother may respond to loud music differently from a teenager. All her subjects should be about the same age.
She hasn’t controlled for <em>wakefulness</em>. A person may respond to music differently when awake than when asleep.
This is called distillation. I think I spelled that right
Answer:
Silver has to give up one electron.
Explanation:
Silver is a transition element and has a partially filled 4d- orbital having 9 electrons and a 5s orbital having 2 electrons in it. In order to achieve stability, silver must have completely filled d-orbital having a maximum number of 10 electrons in it.
Therefore, one electron from 5s orbital jumps to 4d orbital to make it stable. Now, 5s orbital has only one electron, and it will be easy for silver to lose this electron to attain a stable electronic configuration.
