b. 3
c. 5
d. 6
It would be: 2*3 = 6 oxygen atoms
OPTION D IS YOUR ANSWER......
b. False
Answer : Option a) True.
Explanation : A placebo is a substance that is unlikely to affect the dependent variable. True as in a clinical trial for any change in the placebo arm is known as the placebo response, and the difference between this placebo response and the result of no treatment is called as the placebo effect. Therefore, a placebo may be given to any person in a clinical context in order to deceive that recipient into thinking that it is an part of active treatment. It actually resembles a drug but is not an actual active drug, so, it is clear that it will not affect dependent variable.
(2) Ca and Br (4) Na and P
Elements in the same groups shows similar chemical and physical properties. The elements having similar chemical properties are Be and Mg.
A group in periodic table is a column with elements of similar physical and chemical properties.
Both beryllium (Be) and magnesium are in group two with two valence electrons and both are metals. They have similar chemical and physical properties.
Cl is in 17th group and Ar is a 18th group element. They do not show any similarity in chemical properties. One is halogen which is unstable and the second one is noble gas which is stable. Thus no similarity.
Ca is a 2nd group element and Br is 17th group and they are different in chemical properties. One is metal and the second one is halogen with higher electronegativity.
Similarly, Na is in first group and P is 15th group element in periodic table in periodic table and does not show chemical similarities.
Therefore, the elements showing similar chemical properties are Be, Mg thus, option 1 is correct.
To learn more about groups in periodic table, refer the link below:
#SPJ5
atoms are made of 3 types of sub atomic particles- protons, neutrons and electrons
from these 3 particles, electrons are responsible for participating in chemical bonds. therefore chemical properties of elements are based on the number of electrons present.
valence electrons are the number of electrons in the outermost energy shell that are involved in chemical bonds.
atoms with same number of valence electrons are grouped in to columns called groups.
therefore elements of the same group have same number of valence electrons, hence similar chemical properties.
from the options given
only Be and Mg belong to the same group they both belong to group 2 with 2 valence electrons
therefore Be and Mg have similar chemical properties
answer is
1) Be and Mg
FALSE. IT IS MADE OF COPPER THAT IS WHY IT HAS A GREEN TENT.